Would a low albedo substance warm up Mars?
Of course! Actually this is one of the possible ways we have in order to make Mars friendlier 
to humans. This technique is called Terraformation and it inludes the altering of the Mars surface's albedo. However, the feasibility of this plan is yet questionable and there are maybe better ways to achieve this increase in the temperature like CO$_2$ emissions. Here is a nice article discussing exactly this subject.