epoxy will work, but its a mess to use.
Get the powder, remove Reflector/ Optic (and store them somewhere else without touching it!), grab Your girlfriends/sisters/mothers nailpaint in white and clear, cover the Led with some tape, give the "glow area" a good white surface (2 layers min). With the 2nd layer still wet apply a good amount of power, shake, move, ..., the light to have the powder go everywhere You want. USD the light and save excess powder on a sheet of paper (or whatever surface). Wait a bit, apply the clear paint and repeat the process.
Check glow intensity and stop, when the level You want is reached or when there is no more space left (the thinner the paint, the better).
Wait a good time (overnight) then run the light. Led looking to the ceiling, tape removed. When You absolutely positively are sure ther will be no smoke (if any), reassemble the light.
ready to go.
Its a nice thing, even the totally non flashoholics like it.