Renew/repair SLK inner colors

Hello guys, I’ve added the R170 in blue and an interior version of Scharz-Sand. Now I noticed a few places where scratches are on the sand-coloured surfaces and the black primer shines through … My question now to you where I get a suitable color replacement. Something like a paint pencil would be awesome but I don’t think there is one for it or? At least a spray can? Would be grateful for any idea. THX @ all