[Designer 2.0.0.0] Purpose of the Lock Icon in Color Panel

[Mark Oehlschlager]

I've read the Designer Help page on the Color Panel, and I still don't understand the purpose of the Lock icon next to the Color Model selector when in Sliders mode.

I'm free to change the color model from the pop-up selector, regardless of whether or not the Lock icon is set to "locked".

How is one supposed to understand the function of this icon? 

How is one meant to use it?

[loukash]

5 minutes ago, Mark Oehlschlager said:

How is one meant to use it?

affinity.help/designer2/en-US.lproj/pages/Panels/clrPanel.html

[Mark Oehlschlager]

Hi, @loukash.

Here is the relevant passage:

Quote

By default, the color space is locked when using Sliders (e.g., CMYK sliders) to prevent it from changing. This avoids inadvertently swapping to another mode after using swatches or selecting a different object created with a different color mode. When unlocked, the Color panel will remember the color mode that the selected object was created in. This lock only works on the current session; subsequent sessions will use the HSL color wheel as default.

Still, It's not clear. The lock icon does not actually prevent me from changing the color model from the color model Pop-up. And what does the rest of that paragraph mean? Totally confusing.

[loukash]

1 minute ago, Mark Oehlschlager said:

The lock icon does not actually prevent me from changing the color model from the color model Pop-up.

No.

1 minute ago, Mark Oehlschlager said:

And what does the rest of that paragraph mean? Totally confusing.

Hm. English is only my 3rd language but I understand every word. I don't know how to explain it better.
Set up a test document and try it out yourself.

[Mark Oehlschlager]

Thank you, but I think this needs to be addressed by an Affinity staff member, or an expert user who can make it clear with concrete examples.

At the moment, that Lock icon appears to have no use or effect.

To which Affinity staff member should I direct this question?

[loukash]

3 minutes ago, Mark Oehlschlager said:

an expert user

My apologies for not being "expert" enough.  

[Mark Oehlschlager]

Ha!

No problem. I appreciate your reply. Perhaps you are just the expert user I need to chat with, but then what I need from you, in order to help me out, is an explanation that clears up the confusion. Perhaps you have some concrete examples of how to make use of the button that appears to do nothing.

[loukash]

Sigh…

• Locked = every object in your document will display your last selected slider model. Select CMYK, lock it, and every object you click on will show its color based on the CMYK model. 
• Unlocked = each object in your document actually remembers which slider model you've originally applied to it. If there's a rectangle for which you've applied RGB and you unlock the sliders in CMYK mode, then that particular rectangle will display its color in RGB mode.

[loukash]

Interestingly, I just noticed that each object can also remember different modes for stroke and fill. You can e.g. pick your favorite fill in HSL mode but your stroke in CMYK mode. Deselect the object, then lock the panel e.g. in RGB mode. When you unlock the Color panel again and select the object, both original HSL and CMYK modes will be remembered while you switch between fill and stroke. Brilliant!

[Mark Oehlschlager]

So, If I understand you correctly, the Lock Icon does not actually function as a Lock to prevent one from accidentally changing the color model. Rather, the Lock Icon functions as filter, that interprets the color numbers of objects on one's page in the color model currently selected in the color model Pop-up.

Maybe so. But if so, how is that useful? For example, how would this prevent me from picking an RGB color that lies well outside the color gamut of my document's CMYK color space?

[loukash]

7 minutes ago, Mark Oehlschlager said:

the Lock Icon does not actually function as a Lock to prevent one from accidentally changing the color model. Rather, the Lock Icon functions as filter, that interprets the color numbers of objects on one's page in the color model currently selected in the color model Pop-up.

Yep.

7 minutes ago, Mark Oehlschlager said:

how is that useful?

Don't know, I have no immediate use for it. It's one of the "good to know for future use" things.

Much like, in the past, say, 10–15 years I haven't had any use for footnotes or books in InDesign or now in Publisher either. Now we have footnotes and books in v2. That's fine. Perhaps next year I'll have a layout job where I can make use of them. 

13 minutes ago, Mark Oehlschlager said:

how would this prevent me from picking an RGB color that lies well outside the color gamut of my document's CMYK color space?

Why should it? Perhaps you may want to reuse an existing RGB object in a CMYK without having to adjust its colors manually? Much like you can place RGB images and export them for print without having to convert them to CMYK. E.g. PDF/X-4 export can handle placed RGB images fine.

Anyway. There are other problems with color modes that need to be addressed, like K black vs RGB black…

[Mark Oehlschlager]

Well, you don't have to have an answer to this questions, but I'm hoping that someone from Serif has an answer. 

As long as everyone is designing in the sRGB color space for electronic displays, no one need worry about color gamuts. But if one is alternately designing for sRGB devices, then wider color gamut ROMM RGB display devices, and then much smaller color gamut CMYK print output, one needs to be concerned about specifying "in-gamut" colors.

How does Serif expect one to manage these color space gamut issues?

How does the Affinity software prevent someone from (or warn someone against) using the Lab color model sliders to spec an out-of-gamut color for their CMYK document?

[lacerto]

I'll try to explain this by comparing the lock / non-lock feature of Affinity apps with behavior of the same function in InDesign, where the lock behavior is intrinsic (basically always on). The feature is useful (or rather necessary) in environments that can handle multiple color models simultaneously. In Affinity apps this capability is not so obvious because the apps cannot display objects using different color spaces in their full gamut (even when the display allows), so in Affinity apps the currently active "main" color mode and the color profile used basically determines the color space all the colors of the document are displayed in (but with limitations, e.g. CMYK gamut is restricted to sRGB so e.g. cyan tones off the sRGB gamut are not shown realistically). In InDesign objects and images in RGB color space are shown in their intrinsic color space (as long as the display allows), so you would see e.g. very bright reds if you have imported Adobe RGB images even if your document RGB color profile is sRGB, and you would see full PANTONE color gamut defined in Lab, and also full CMYK gamut.

By default the lock is turned on, which is important, because if the lock is in off position, not only does the color model of the Color panel constantly change according to the color model each selected object has been defined in, but in addition: having an object (e.g. text or shape) selected and then switching the color model (within Color panel) will actually change the color model for the selected object, which involves conversion e.g. from wider gamut to narrower (typically RGB to CMYK), and if switched back, a new conversion, resulting in different color value the object initially had. In extreme, you could "inadvertently" do something like this (how much colors would change on each successive switch depends on underlying profiles and their gamut differences):

This does not basically happen in InDesign, since the lock is always on: you need to explicitly use the sliders or type in color values to cause conversion from one color space to another (similarly as in Affinity apps when the lock is turned on). On the other hand, InDesign does change the color mode of the selected object when the color model (current view in Color panel) is changed, by using ad-hoc hidden swatches so if swatches are created based on object selections, they would be defined in the color model shown in the Color panel. In Affinity apps, the internally saved color model would be used while a locked Color panel would show the color in the user-selected color model. This can be quite confusing, and I do not think that the behavior of this feature is explained well anywhere in the documentation.

Anyway, the lock is quite useful within Affinity apps, since as mentioned, the intrinsic color values are not shown realistically. By having the lock turned on as a "standard feature", and then turning it temporarily off, the user can (most often) check the true color values of an object (instead of ad-hoc conversion values it would have in different color modes when e.g. exported using the currently active document color profiles). Another way to do this would be creating swatches in a document palette (dragging a color picker on top of an object would in contrast always show the color values in the color space determined by the current document color mode). For an important feature it is unfortunate that the UI makes it pretty difficult to tell whether the lock is actually turned on or off!

 

[Mark Oehlschlager]

@lacerto

Thank you for that. I think I'll need to read through that a few times to get it, but there are bits I can pick up on.

Try this:

Start a new CMYK document. The working color space by default is U.S. Web Coated (SWOP), and, of course, this is a smaller color space than any RGB or Lab color space.

Next, draw a square shape and fill it with 100% Magenta. Duplicate this square to the right.

Next, select the square on the right. Go to the Color Panel, insure that the color model Lock is "on", and then use the pop-up menu to switch the color model to Lab. You should see the following values: L: 52, A: 81, B: -7.

You will notice that the Lab sliders allow one to push the A Opponent slider further to the right for a more intense Magenta – one that lies well outside of the color gamut of the CMYK color space.

While the right square is still selected, If you then slide the A Opponent slider all the way to the right so that A = 127, I think you will notice NO change in the appearance of the right square's color. Why? My guess is that the gamut of the document's smaller CMYK color space is clipping the value of the more intense magenta color from the larger Lab color model and space.

So, the fact is this (and let's leave the display monitor out of this for now): the working color space of your document determines the limit of the colors that can be represented. And although you may use the sliders from color models/spaces that are larger than your document's color space, you need to be aware that though you can dial in values for colors that are well outside of your document's color space, they will be clipped back to the nearest approximate color in the smaller document color space.

There's more to be learned and said on this topic, including how and when to use the Lock icon. But perhaps others can chime in on this.

[lacerto]

7 minutes ago, Mark Oehlschlager said:

You will notice that the Lab sliders allow one to push the A Opponent slider further to the right for a more intense Magenta – one that lies well outside of the color gamut of the CMYK color space.

Yes, this is intentional. You can define colors that are beyond the gamut determined by the color profile of the currently active color mode (in your example all colors would be limited to CMYK color space determined by US Web Coated, which would additionally be limited to sRGB, so that e.g. cyans that are off sRGB would not be shown realistically). If you change the color mode to RGB and have there e.g. Adobe RGB, you would see your Lab defined Magenta much brighter.

17 minutes ago, Mark Oehlschlager said:

they will be clipped back to the nearest approximate color in the smaller document color space.

But only in active view. So as said, if you switch the document color mode, you would see colors clipped by the CMYK mode. Or, if you export to RGB modes, you would get that Magenta brighter without needing to switch the document color mode.

[Mark Oehlschlager]

I believe it’s the document’s color space that determines what can be displayed in document, regardless of whether or not one uses a larger color model to define colors. CMYK < sRGB < Adobe RGB < ROMM RGB < Lab. 
 

What seems to be missing from the color palette is a warning when one chooses a color outside the gamut of the document’s color space. Also a clear explanation of how and when to use the Lock. 

[lacerto]

4 hours ago, Mark Oehlschlager said:

CMYK < sRGB

CMYK is mostly narrower but there are CMYK colors that cannot be rendered in sRGB. But what is odd is that CMYK in Affinity apps is restricted by sRGB even if the underlying RGB color space is wider (top left is in Adobe RGB color space and has C100 defined; on the right side of it is the same document in CMYK mode and C100 is now restricted to sRGB, as can be seen when viewing the bottom row where C100 is shown in sRGB color document, and then in CMYK color mode):

Warnings might be useful, but the actual problem is that object color spaces cannot be shown realistically, so you cannot have e.g. an sRGB document color profile and have PANTONE inks defined in L*a*b showing in full monitor gamut, nor can you see e.g. placed Adobe RGB image shown in Adobe RGB gamut in an sRGB document [in addition to more obvious problem of not being able to see RGB color gamuts in documents using a CMYK color mode]. You kind of have a permanent soft proof turned on (and even that limited by factors like shown above).

EDIT: Here is a comparison (note that the forum scales the colors to sRGB but the relative differences still show to some extent):