Pale Rider vs Flash Gitz Yellow

How close are they?

ΔE 48.7, loose: different enough that you should pick on purpose. Flash Gitz Yellow is a little darker, much more saturated, warmer than Pale Rider.

Can I use Flash Gitz Yellow instead of Pale Rider?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 49). Flash Gitz Yellow is a little darker, much more saturated, warmer than Pale Rider.

Can I use Pale Rider instead of Flash Gitz Yellow?

The same difference applies the other way round: Pale Rider is a little lighter, much more muted, cooler.

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.