Trollslayer Orange vs Ruby Red

How close are they?

ΔE 16.4, loose: different enough that you should pick on purpose. Ruby Red is a little darker, more saturated, cooler than Trollslayer Orange. They are different kinds of paint: Citadel Trollslayer Orange is an opaque base/layer paint and Green Stuff World Ruby Red is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.

Can I use Ruby Red instead of Trollslayer Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Ruby Red is a little darker, more saturated, cooler than Trollslayer Orange. They are different kinds of paint.

Can I use Trollslayer Orange instead of Ruby Red?

The same difference applies the other way round: Trollslayer Orange is a little lighter, more muted, 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.