Orange vs True Blood

How close are they?

ΔE 15.5, loose: different enough that you should pick on purpose. True Blood is noticeably darker, more saturated than Orange.

Can I use True Blood instead of Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). True Blood is noticeably darker, more saturated than Orange.

Can I use Orange instead of True Blood?

The same difference applies the other way round: Orange is noticeably lighter, more muted.

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.