Can someone tell me how to read a paint card? (colors, designers)

[gentlearts]

I figure that it would be a lot easier to choose compatible colors if I understood the info that is on the back of a paint card.
There is the percentage of red, blue, and yellow, and then there's a bunch of other statistics.
For example, how can I tell which is the warmer gray when comparing several? How can I tell the coolest red when comparing samples?
How would I choose, for example, a red and a gray which were most compatible to each other by the statistics on the back of the paint card?

[chet everett]

The basic "fan deck" is a key tool for both painters to ask for the proper mix of tints and designers to have access to all the manufactures colors.

Some include info about surface finish adjustments (glossier or flatter versionsmof some base will distort the formula more) while other include info about family color comparability -- http://www.thepaintedsurface.com/howchoosecolors.php

Some nicer paint shops will have the various "color families" (warm, cool, neutral, pastel, et) arranged OR in separate "design binders". Most interior architecture firms also have these.

I have seen services on the web that will translate one manufacturer's color formula to other's base , but they charge for this.