M&P colorants are different than CP colorants. You can use common food dye like at the market for M&P. I wouldn't use it unless it says safe for CP soaping. I haven't seen any discussion on using food dyes in CP soap and I expect there's a reason for that, probably the lye eats up the colors.
I rather like the color that olive oil soap has, usually a milky light green. It's a kind of nice wholesome color. You might like it.