Menoth White Highlight vs White

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. White is a little lighter, much more muted than Menoth White Highlight.

Can I use White instead of Menoth White Highlight?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). White is a little lighter, much more muted than Menoth White Highlight.

Can I use Menoth White Highlight instead of White?

The same difference applies the other way round: Menoth White Highlight is a little darker, much more saturated.

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.