Trollblood Highlight vs Rus. AF Grey Prot. Coat

How close are they?

ΔE 21.2, loose: different enough that you should pick on purpose. Rus. AF Grey Prot. Coat is a little lighter, cooler than Trollblood Highlight.

Can I use Rus. AF Grey Prot. Coat instead of Trollblood Highlight?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Rus. AF Grey Prot. Coat is a little lighter, cooler than Trollblood Highlight.

Can I use Trollblood Highlight instead of Rus. AF Grey Prot. Coat?

The same difference applies the other way round: Trollblood Highlight is a little darker, warmer.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.