ΔE 11.7, fair: the same colour family, but not a straight swap. Radiant Yellow is a little lighter, cooler than Green Sun.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Radiant Yellow is a little lighter, cooler than Green Sun.
The same difference applies the other way round: Green Sun 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.
See Green Sun on the colour wheel See Radiant Yellow on the colour wheel
All matches: Green Sun equivalents · Radiant Yellow equivalents