Voodoo Shade vs Hellion Red Wash

How close are they?

ΔE 26.7, loose: different enough that you should pick on purpose. Hellion Red Wash is noticeably lighter, cooler than Voodoo Shade.

Can I use Hellion Red Wash instead of Voodoo Shade?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Hellion Red Wash is noticeably lighter, cooler than Voodoo Shade.

Can I use Voodoo Shade instead of Hellion Red Wash?

The same difference applies the other way round: Voodoo Shade is noticeably darker, 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.