How to make checkbox tick colour follow skin

[Ninja_beaver]

I'm trying to make a checkbox follow the current skin like the ones in preferences do, e.g. here with the DarkRED metro skin:
I tried using

Code

Setting_GetSkinElementColour()

and looking through the various combinations of options, but none of them seemed to correspond to the red tick colour.  I'm wondering how to get the correct colour.

[psychoadept]

I was under the impression that the tick mark is an image file, so you'd have to extract it from another skin and recolor it. But I could be wrong, I haven't messed with skinning in a long time.