Wyvern Fury vs Sanguine Highlight

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Sanguine Highlight is a little lighter, more saturated than Wyvern Fury.

Can I use Sanguine Highlight instead of Wyvern Fury?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Sanguine Highlight is a little lighter, more saturated than Wyvern Fury.

Can I use Wyvern Fury instead of Sanguine Highlight?

The same difference applies the other way round: Wyvern Fury is a little darker, more muted.

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.