Sorry, but you are NOT being very clear - are you interested in:
A: using CMYK ink to SIMULATE a Pantone color when printing on light blue paper ?
or -
B: are you planning on using a spot ink and printing on light blue paper ?
Me, I would do what they do when they print the yellow pages - that is, they do NOT print on yellow paper, they print on white paper and they yellow you see is actually yellow ink ( yeah, don't believe me, get a loupe and see for yourself )
Also, if A, please explain to the customer that inks are transparent, so, that is totally impossible with light Pantone colors like :
http://www.pantone.com/color-finder/2001-UP
it will look green.
if B, then ( again ) same example, you can print white down first (so, white, then the pantone )