What is the difference between rouge theatre and ruby

Ruby is essentially a tad bit lighter than Rouge Theatre, it has more of a fruit punch red with blue purple/blue undertones.

Rouge Theatre is a straight dark red.. I can't really tell about the undertones.
 
RT definitely has more blue undertones and to me seems close to a cranberry color. I think Rubisse also has blue undertones, but less than RT and I would say that Rubisse is closer to red, then RT. But to my eye, neither is a pure red.
 
ruby has a kind of flourescent, pop, punch. with blue/cherry undertones. to me rt has both blue and orange tones in it. complex color usually with some variation. to me, ruby is very evenly colored. and rarely veiny.