Royal Robes vs Cygnar Blue Base

How close are they?

ΔE 14.5, fair: the same colour family, but not a straight swap. Cygnar Blue Base is a little darker, more saturated, warmer than Royal Robes. They are different kinds of paint: Army Painter Royal Robes is a one-coat contrast-style paint and Formula P3 Cygnar Blue Base is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.

Can I use Cygnar Blue Base instead of Royal Robes?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Cygnar Blue Base is a little darker, more saturated, warmer than Royal Robes. They are different kinds of paint.

Can I use Royal Robes instead of Cygnar Blue Base?

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