Bold Titanium White vs Off-White

How close are they?

ΔE 8.5, close: similar, with a visible difference side by side. Off-White is a little darker, more saturated than Bold Titanium White.

Can I use Off-White instead of Bold Titanium White?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Off-White is a little darker, more saturated than Bold Titanium White.

Can I use Bold Titanium White instead of Off-White?

The same difference applies the other way round: Bold Titanium White is a little 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.