Bony Spikes vs 'Jack Bone

How close are they?

ΔE 18.5, loose: different enough that you should pick on purpose. 'Jack Bone is a little darker, much more saturated, cooler than Bony Spikes.

Can I use 'Jack Bone instead of Bony Spikes?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). 'Jack Bone is a little darker, much more saturated, cooler than Bony Spikes.

Can I use Bony Spikes instead of 'Jack Bone?

The same difference applies the other way round: Bony Spikes is a little lighter, much more muted, 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.