Frostheart vs Fluorescent Blue

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Fluorescent Blue is a little darker, more saturated than Frostheart. They are different kinds of paint: Citadel Frostheart is a one-coat contrast-style paint and Vallejo Fluorescent Blue is a fluorescent or effect paint, so they won’t behave the same on the model even where the colour is close.

Can I use Fluorescent Blue instead of Frostheart?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Fluorescent Blue is a little darker, more saturated than Frostheart. They are different kinds of paint.

Can I use Frostheart instead of Fluorescent Blue?

The same difference applies the other way round: Frostheart is a little lighter, 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.