Light Tone vs Blush Red

How close are they?

ΔE 42.4, loose: different enough that you should pick on purpose. Blush Red is a little lighter, cooler than Light Tone.

Can I use Blush Red instead of Light Tone?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 42). Blush Red is a little lighter, cooler than Light Tone.

Can I use Light Tone instead of Blush Red?

The same difference applies the other way round: Light Tone is a little darker, 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.