Calth Blue Clear vs Phthalo Blue (Green Shade)

How close are they?

ΔE 12.9, fair: the same colour family, but not a straight swap. Phthalo Blue (Green Shade) is a little darker, more saturated than Calth Blue Clear.

Can I use Phthalo Blue (Green Shade) instead of Calth Blue Clear?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Phthalo Blue (Green Shade) is a little darker, more saturated than Calth Blue Clear.

Can I use Calth Blue Clear instead of Phthalo Blue (Green Shade)?

The same difference applies the other way round: Calth Blue Clear 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.