Dark Blue Tone vs Targor Rageshade

How close are they?

ΔE 32.9, loose: different enough that you should pick on purpose. Targor Rageshade is noticeably lighter, more muted, warmer than Dark Blue Tone.

Can I use Targor Rageshade instead of Dark Blue Tone?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Targor Rageshade is noticeably lighter, more muted, warmer than Dark Blue Tone.

Can I use Dark Blue Tone instead of Targor Rageshade?

The same difference applies the other way round: Dark Blue Tone is noticeably darker, more saturated, cooler.

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.