Red Tone vs Targor Rageshade

How close are they?

ΔE 38.2, loose: different enough that you should pick on purpose. Targor Rageshade is much more muted, cooler than Red Tone.

Can I use Targor Rageshade instead of Red Tone?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 38). Targor Rageshade is much more muted, cooler than Red Tone.

Can I use Red Tone instead of Targor Rageshade?

The same difference applies the other way round: Red Tone is much 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.