Possibly, yes. There are several factors at play here (freshness of LME is an issue), you can find tons of threads comparing the two but I'll tell you I stick to just DME now, when I do need to use extract. It has a much better shelf life, it yields more gravity points than LME (you will use less DME in a brew than you would LME), it doesn't scorch as easily, and I think it's cleaner to use. Sticky LME can make a real mess.
Some people also attribute a "twangy extract" taste to LME (usually another freshness issue).
Either way, LME or DME, I'd add them late, search for late extract additions for more info on this. IF you add them later, they'll affect your color less.
So now that I've gone off on this rant, yes, LME may produce a darker beer than DME.