Good luck, both are totally different/proprietary and I don't believe a full cross reference has been published. You might need to physically/instrumentally compare a swatch.
By ansi paint codes do you mean FEDERAL STANDARD 595B COLORS?
Like mcgyver says, good luck. We use a mix of specs because different processes (painting V silkscreen V cellotape appliques etc) prefer different systems, ral & Pantone are the two I've seen most.
We tried finding equivalents so we'd know that when we wanted 'company gray' we'd just spec Fed 595B 16492, or Fed 595B 11120 for 'company red' etc. but it never really went anyway.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:
I think we may have a few RGB, not sure about CMYK doesn't look familiar.
Our marketing folks can be very picky, we tried the arbitrarily matching stuff and it didnt' work as I recall. I think we may have our own samples/chips for some aesthetically important item.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies: