Ive recently begun experimenting with mask spraying and changing the colour of my mask with great results
as you can see, it turned out great. However, being as flexable as it is, the sides are easily fractured if bent more than 45 degrees inwards. I didnt need to sand it down, i just applied acrylic plastic paint and sealed it with a clear seal. Its still as of yet untested on field however it will soon be subject to a brutal shoot out on a walk on
It might be an idea though to consider a more sturdy mask like Grillz or I4's to paint/colour change.