Phthalo Green (Yellow Shade) vs Sick Green

How close are they?

ΔE 12.8, fair: the same colour family, but not a straight swap. Sick Green is a little lighter, warmer than Phthalo Green (Yellow Shade).

Can I use Sick Green instead of Phthalo Green (Yellow Shade)?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Sick Green is a little lighter, warmer than Phthalo Green (Yellow Shade).

Can I use Phthalo Green (Yellow Shade) instead of Sick Green?

The same difference applies the other way round: Phthalo Green (Yellow Shade) is a little darker, 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.