Flood paint and color picker

[Jae_]

Hey there,

I'm scratching my head a bit at the moment with Affinity Photo (V1 on mac).  I'm attempting to do some pallets in greyscale which I'll then use flood select to explore the value range of the image I'm working in. Long story short, what's happening is that I:

1. Set my color to 8 on the grey scale slider (100% opacity)
2. Use the elliptical marquee tool to set my "pallet" to paint
3. Use the flood fill tool to paint the selection
4. Immediately go to the color picker tool and test the area I just filled...

BUT!!! The color picker tells me that it was filled with 10 not 8 on the greyscale.  This has shown up for me mostly in the lower values but I've seen it all the way up to 59 (color picker said 58) and it's not limited to odds or evens (26 gives 27) Oddly enough if I fill with 10 the color picker tells me it's 13 too... Sigh.

What's going on here and is there anyway I can correct this so that I know what is actually getting filled?

Edited December 13, 2024 by Jae_

[NotMyFault]

It really depends on multiple aspects:

• color format of the document
• color profile of the document 
• color mode of the color panel

Affinity will automatically convert color values when needed, but this conversions may lead to unexpected results. As you say you are trying greyscale: 

the color values differ between e.g. RGB (HSL) and GREY color formats. 
 

To be on the save side, use RGB/8 or RGB/16 color formats with sRGB color profile, and use RGB or HSL in color panel.

Do not mix with GREY color formats.

Alternatively,  use all in GREY format, but consider that the default and only greyscale color profile results in deviating colors for darker tones.