I recently finished the ratio Toad kit.
The whole thing was sprayed halfords white primer then humbrol 64 light grey. The solebar and below are revell matt black and handrails etc painted white.
I wanted to have the van allocated to Croesnewydd although I have no photos of a BR era van with this legend. The areas for black were masked and sprayed.
As @Mikkel suggested I used an HMRS sheet to construct the croesnewydd but only had the general wagon sheet