Red and blue Antimo Caputo 00 flour
Caputo Rosso (red) might have a slightly higher gluten content (~12-13%) than Blu (blue) (~10-12%) and higher stability. But mostly the blue one is just more of a niche product meeting the highest standards for traditional Neapolitan pizza.

Here are spec sheets directly from their web site:  


BLUE: http://caputoflour.com/wp-content/uploads/2013/07/00-Pizzeria-SPECS.pdf
Extracted from their page:
"for the demanding technical pizzaioli", "recognized by the leading Neapolitan pizza certification associations", "ideal for classic Neapolitan Pizza in wood fired, gas or electric ovens", "produces a very soft and flavorful crust with optimal hydration", "high-quality protein and gluten result in a consistent long-rise dough.", "milled specifically for use at temperatures above 700°F", "Growth: 1’50”-2’00”; Stability: 8’-10’; …"
RED: http://caputoflour.com/wp-content/uploads/2013/07/00-Rinforzata-Flour-SPECS.pdf
Extracted from the page:
"higher protein and gluten content and water absorption is ideal for long-rise doughs", "obtains soft texture", "ideal for pasta, pastry, specialty breads and pizza", "Growth: 2’00”-3’00”; Stability: 12’-14’; …"


And since they both say ideal for pizza - nothing can go wrong ;-)



And if you don't know what the differences in stability times mean ...
I find this page quite informative:
http://www.wheatflourbook.org/p.aspx?tabid=33
Flour science is almost like airports ... with all the arrival and departure times =D