Sun Stone vs Fiendish Yellow

How close are they?

ΔE 11.4, fair: the same colour family, but not a straight swap. Fiendish Yellow is a little darker, more muted than Sun Stone.

Can I use Fiendish Yellow instead of Sun Stone?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Fiendish Yellow is a little darker, more muted than Sun Stone.

Can I use Sun Stone instead of Fiendish Yellow?

The same difference applies the other way round: Sun Stone is a little lighter, more saturated.

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.