Stormfang vs Teal

How close are they?

ΔE 22.3, loose: different enough that you should pick on purpose. Teal is a little lighter, much more saturated, warmer than Stormfang.

Can I use Teal instead of Stormfang?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Teal is a little lighter, much more saturated, warmer than Stormfang.

Can I use Stormfang instead of Teal?

The same difference applies the other way round: Stormfang is a little darker, 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.