Icon colour changes from screen to screen

I’ve noticed a some strange behaviour in the way the colour in some icons are rendered/displayed between two monitors.
Specifically the visibility lightbulb icons appear to be yellow when the tool palettes are in my external monitor, but they appear orange when I move the tool palette to my macbook pro monitor.

It’s not a serious problem or anything, it’s just really weird, anyone else encounter this?

Also, I’ve captured the colour difference in screenshots, so the colours are actually being rendered differently, it’s not just a difference in the display.

Here is a custom tool palette and the visibility palette in my external monitor

And the same to palettes moved over to my macbook pro monitor

I made several custom buttons and icons, those are the ones that don’t change colour while the standard lightbulb icons do for some reason