ΔE 10.5, fair: the same colour family, but not a straight swap. Fluor Red is a little lighter, more saturated than Angron Red Clear. They are different kinds of paint: Citadel Angron Red Clear is an opaque base/layer paint and Green Stuff World Fluor Red is a fluorescent or effect paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Fluor Red is a little lighter, more saturated than Angron Red Clear. They are different kinds of paint.
The same difference applies the other way round: Angron Red Clear is a little darker, 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.
See Angron Red Clear on the colour wheel See Fluor Red on the colour wheel
All matches: Angron Red Clear equivalents · Fluor Red equivalents