Lemon Yellow vs Hexos Palesun

How close are they?

ΔE 15.3, loose: different enough that you should pick on purpose. Hexos Palesun is a little darker, much more muted than Lemon Yellow.

Can I use Hexos Palesun instead of Lemon Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Hexos Palesun is a little darker, much more muted than Lemon Yellow.

Can I use Lemon Yellow instead of Hexos Palesun?

The same difference applies the other way round: Lemon Yellow is a little lighter, 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.