What color epoxy? - low vision related

[Evil_Fiz]

I suffer from retinal degeneration which makes it difficult for me to distinguish differences in low-contrast situations. I plan to purchase Black AND White epoxy. The intent is to create a light grey by mixing white and black epoxy in a ~90%/10% - 95%-5% ratio respectively, for the interior, underside, trunk, and engine compartment, to provide better visibility in the future. My dilemma is that I don't know what color to use on the exterior as it pertains to sanding visibility.

-- Between Black and White epoxy, which will have the highest contrast between sanded and unsanded areas? (i suspect Balck)
(I plan to use epoxy wherever possible instead of 2K primer, poly primer, or filler.)

-- In areas where a thicker layer of epoxy may be needed to level the surface, will I get a thicker build by spraying or rolling it on?
If I understand it correctly longer induction time means thicker epoxy at application time.

Thanks to everyone for all your help and advice so far.
Emil

 

[Lizer]

The black contrasts with about anything so well. If you spray your black first and then gray as a second coat, it becomes easy to tell when you’re hitting the black. White would not cover the black as well and it doesn’t cover great period.

For a novice I’d stick with going with 2k or poly instead of trying to do it all epoxy. It’s just so slow to build with epoxy, I’ll probably never do it.