ΔE 12.3, fair: the same colour family, but not a straight swap. Knight-Questor Flesh is noticeably lighter than RAL 8012 Rotbraun.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Knight-Questor Flesh is noticeably lighter than RAL 8012 Rotbraun.
The same difference applies the other way round: RAL 8012 Rotbraun is noticeably darker.
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 RAL 8012 Rotbraun on the colour wheel See Knight-Questor Flesh on the colour wheel
All matches: RAL 8012 Rotbraun equivalents · Knight-Questor Flesh equivalents