The paint finish on most diecasts is enamel, I beleive.So I guess it would be wise to take some precautions with the paint dust.The composition of the metal contains no lead,which is good news.
To take the shine off the enamel paint I use 600 grit sandpaper to dull it down to a flat finish.Acrylics seem to stick well to a sanded surface,if not mix in a little gesso.The surface that I am presently dealing with is mostly black so I have it easy and I am using black gesso.Gesso comes in black ,white, grey,and burnt umber.
Chaulk pastels come in all colors and stick really well to a sanded surface.I use those soft makeup brushes that women use when applying makeup or cops use when dusting for fingerprints.They come in all sizes so you will have to experiment a bit here.The more you load up the brush the more color will be transfered.Try to build the color up in subtle layers.
To grind up the pastels ,I use ordinary sandpaper and dunk my brush into the fine dust. Cheers! John.
