Scarab Red vs Ruby Red

How close are they?

ΔE 8.7, close: similar, with a visible difference side by side. Ruby Red is a little lighter, more saturated than Scarab Red.

Can I use Ruby Red instead of Scarab Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ruby Red is a little lighter, more saturated than Scarab Red.

Can I use Scarab Red instead of Ruby Red?

The same difference applies the other way round: Scarab Red 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.