ΔE 12.1, fair: the same colour family, but not a straight swap. Undead Dragon is a little darker, more muted, cooler than Howling Sand.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Undead Dragon is a little darker, more muted, cooler than Howling Sand.
The same difference applies the other way round: Howling Sand is a little lighter, more saturated, warmer.
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 Howling Sand on the colour wheel See Undead Dragon on the colour wheel
All matches: Howling Sand equivalents · Undead Dragon equivalents