Ice Storm vs Lendanis Grey

How close are they?

ΔE 19.0, loose: different enough that you should pick on purpose. Lendanis Grey is noticeably darker, more muted, warmer than Ice Storm.

Can I use Lendanis Grey instead of Ice Storm?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Lendanis Grey is noticeably darker, more muted, warmer than Ice Storm.

Can I use Ice Storm instead of Lendanis Grey?

The same difference applies the other way round: Ice Storm is noticeably lighter, 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.