Safety Orange vs Yellow Ochre

How close are they?

ΔE 15.0, loose: different enough that you should pick on purpose. Yellow Ochre is more muted, cooler than Safety Orange.

Can I use Yellow Ochre instead of Safety Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Yellow Ochre is more muted, cooler than Safety Orange.

Can I use Safety Orange instead of Yellow Ochre?

The same difference applies the other way round: Safety Orange is 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.