'81 Laser Paint Codes

[Macanleister]

Hiya, hope this hasn't been posted somewhere else. I'm the owner of an '81 KA Laser, and I'm trying to get hold of some paint to patch up rust spots. Problem is, it doesn't seem to have a sticker with the paint code. I've checked the edges and doorjambs of all of the doors (as my google searches told me to), as well as under the hood and in the spare wheel space, but no joy. The colour is a very light grey, which looks extremely pale beige in some lights. Anyone got any ideas how I could find the correct colour code for it?