Specific Color Removal

[JFan]

Hi all, 

there's a very faint green/purple cast at along the focus line (around 30% up from the bottom). The top half of it is green, while bottom half is purple; I'm pretty sure it's just CA from my lens that's adapted.

Does anyone have any suggestions on how to remove it? I'm sure it shouldn't be too complicated, but I've never been good at super fine/specific selection stuff

Thanks,

Jon

[NotMyFault]

Maybe the defringe filter could do the job? Does not need any masking at all. 
A new tutorial has been published recently. 

[DWright]

You can select these areas and then use the colour balance adjustment to change the tonal range of the selection.

[David in Яuislip]

Try an HSL adjustment layer
Click the green circle, set saturation to -100% and adjust the 3rd node as shown
Click the magenta circle, set saturation to -100%

[PixelPest]

@David in Яuislip is this the specified area? Just asking.

[David in Яuislip]

5 minutes ago, PixelPest said:

 is this the specified area? Just asking.

Sorry, I don't understand the question

[PixelPest]

I can´t spot any purple in that area you´re correcting and showing in the thumbnails. Maybe I´m just not able to.

[David in Яuislip]

It's very subtle. If the magenta HSL layer is adjusted to +100 then it shows. Maybe the OP sees more from the original rather than the screenshot I used

[Lisbon]

there's a very faint green/purple cast at along the focus line (around 30% up from the bottom)

I will be honest, but I had a hard time to find it.
I believe most of us won't even see it.

See if this works for you.
Duplicate the background and change the blend mode to colour.
On the BG copy, with the Clone Brush Tool set to 0% hardness start cloning from a close area (Similar brightness).
This will only affect colour. Not texture.

This strange colours are due to support layers that I used just see better the problem.
On your computer it will look fine.

[JFan]

Thank you all for your responses and help! 

@Lisbon I ended up going with your method, just made the most sense to me. It took me a while to notice the color cast too, but it bothered me once I did 😅

[PixelPest]

So this is the place I suspected - not the emblem. What kind of "shield" is this BTW? Looks like from the future.

[JFan]

Yeah.

 

Also, the shield's just a fancy fidget toy lol.

[PixelPest]

3d printed?

 

[JFan]

Not sure how it's manufactured. Made of zirconium, from a Facebook group called "EDC Loong"

[PixelPest]

OMG: https://www.youtube.com/watch?v=czv1-oHsOyQ

 

Someone in the family bought castanets and I thought I was badly off.  Yikes.

[iconoclast]

My alternative solution: create an empty new pixel layer above the image layer, choose the Blend Mode "Colour", pick up the blue/grey colour from the neighbour-pixels and paint with the Paintbrush over the areas with the wrong colours. It is a more subtle retouch, I think.