ΔE 11.7, fair: the same colour family, but not a straight swap. Sunny Skin Tone is a little lighter, more muted, warmer than Tiamat Orange.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Sunny Skin Tone is a little lighter, more muted, warmer than Tiamat Orange.
The same difference applies the other way round: Tiamat Orange is a little darker, more saturated, 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.
See Tiamat Orange on the colour wheel See Sunny Skin Tone on the colour wheel
All matches: Tiamat Orange equivalents · Sunny Skin Tone equivalents