ΔE 7.4, close: similar, with a visible difference side by side. Faded Red is a little lighter, cooler than Ruby Red.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Faded Red is a little lighter, cooler than Ruby Red.
The same difference applies the other way round: Ruby Red 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.
See Ruby Red on the colour wheel See Faded Red on the colour wheel
All matches: Ruby Red equivalents · Faded Red equivalents