Colorants for slip

Help! Today my son's teacher asked if I could volunteer in his class making masks this Thursday. From past teaching experience, I've decided that glazes are a royal pain in the ass, so I want to use slip.

I've got a reliable slip recipe (from Odyssey) but do not know what to use for colorants. I do not have any stains, but I do have all the usual oxides and carbonates. I'm trying to avoid an unnecessary trip to Highwater if I can make do with what I have.

Can anyone tell me what oxides are good and in what amounts? Thanks!