Again, like the dark orange colour, they're car paints that were made to match a colour used by a specific brand of car. I only kept a record of the reference code the store used to look up the colour, so I don't know what cars they came from.
If you know of a store selling cars, car parts, etc., I suggest looking to see if they have a paint mixer. They might have a catalog of car colours for you to to look through and match LEGO colours to, or a colour scanner. If you live in the UK, I'd recommend Halfords.
Though the dark turquoise is a very close match, the purple colour I used on Kaj and Onepu isn't the best match (though it is the best I've found). You'd have a hard time trying to find an exact match as LEGO purple is quite a peculiar colour.