Everyone needs a great red bag and a great basic black--so if the rouge and the black B-bags fill that need keep them. If they don't, then consider selling one of them off. That's my first idea.
If you just can't part with the "basics", i.e. red and black. Then look at the blue and lilac. I'm not super familiar with b-bags, but I think those are both more pastely colors. Figure out which one gets used less or doesn't fit in your life as much and let that one go...
If you're getting a black Chanel, you might consider letting your black b-bag go.... I love having color in my "fun" purses but think that black or red is best for the "classics."
