ΔE 7.7, close: similar, with a visible difference side by side. Fluor Orange is a little darker, more saturated than Violent Vermillion. They are different kinds of paint: Army Painter Violent Vermillion is an opaque base/layer paint and Green Stuff World Fluor Orange is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Fluor Orange is a little darker, more saturated than Violent Vermillion. They are different kinds of paint.
The same difference applies the other way round: Violent Vermillion is a little lighter, 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 Violent Vermillion on the colour wheel See Fluor Orange on the colour wheel
All matches: Violent Vermillion equivalents · Fluor Orange equivalents