Demigod Flames vs Solar Flare

How close are they?

ΔE 16.6, loose: different enough that you should pick on purpose. Solar Flare is a little lighter, much more saturated than Demigod Flames.

Can I use Solar Flare instead of Demigod Flames?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Solar Flare is a little lighter, much more saturated than Demigod Flames.

Can I use Demigod Flames instead of Solar Flare?

The same difference applies the other way round: Demigod Flames is a little darker, much 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.