It's easy to say after the fact that Colors was a dud, because it ended up turning out that way. Instagram, which is similar, ended up being a good investment.
My point is that VC financing is high-risk, so things that you may think of as being high risk investments, or "duds", are probably potential investments.
VCs also have to deal with the agency effect. If five firms jump on one startup and your firm doesn't, and that startup ends up being successful/gets a return, you stand to lose your clients as a VC.