Darwin held some views that would be considered racist by today's standards, but in the context of his own time his views on race where notably liberal. It only makes sense to denounce Darwin as "racist" if you hold to the ahistorical "all dead, white European males are racist almost by definition" standard of the radical left. Do you hold to that standard? Because if you do, you must also denounce Abraham Lincoln as racist. Indeed Lincoln was much more explicit and definite on the inferiority of blacks than Darwin ever was.
Here are some of Darwin's comments on race. You can see the stereotypes he embraces here -- e.g. "cheerful" negroes, "diminutive" Portuguese with "murderous countenances" (although he was referring to slave holders) -- but note the dates and consider the virulent and negative racism that was a commonplace at the time:
"I have watched how steadily the general feeling, as shown at elections, has been rising against Slavery. What a proud thing for England, if she is the first European nation which utterly abolish is it. I was told before leaving England, that after living in slave countries: all my options would be altered; the only alteration I am aware of is forming a much higher estimate of the Negros character. It is impossible to see a negro & not feel kindly toward him; such cheerful, open honest expressions & such fine muscular bodies; I never saw any of the diminutive Portuguese with their murderous countenances, without almost wishing for Brazil to follow the example of Haiti [where the slaves successfully revolted and gained their freedom]; & considering the enormous healthy looking black population, it will be wonderful if at some future day it does not take place." -- Charles Darwin to Catherine Darwin (May 22 - July 14 1833) The Correspondence of Charles Darwin Vol. 1 1821-1836 (1985), pp. 312-313"A few days afterwards I saw another troop of these banditti-like soldiers start on an expedition against a tribe of Indians at the small Salinas, who had been betrayed by a prisoner cacique...Two hundred soldiers were sent; and they first discovered the Indians by a cloud of dust from their horses' feet, as they chanced to be travelling...The Indians, men, women, and children, were about one hundred and ten in number, and they were nearly all taken or killed, for the soldiers sabre every man. The Indians are now so terrified that they offer no resistance in a body, but each flies, neglecting even his wife and children; but when overtaken, like wild animals, they fight against any number to the last moment. One dying Indian seized with his teeth the thumb of his adversary, and allowed his own eye to be forced out sooner than relinquish his hold. Another, who was wounded, feigned death, keeping a knife ready to strike one more fatal blow. My informer said, when he was pursuing an Indian, the man cried out for mercy, at the same time that he was covertly loosing the bolas from his waist, meaning to whirl it round his head and so strike his pursuer. "I however struck him with my sabre to the ground, and then got off my horse, and cut his throat with my knife." This is a dark picture; but how much more shocking is the unquestionable fact, that all the women who appear above twenty years old are massacred in cold blood! When I exclaimed that this appeared rather inhuman. he answered, "Why, what can be done? they breed so!"
Every one here is fully convinced that this is the most just war, because it is against barbarians. Who would believe in this age that such atrocities could be committed in a Christian civilized country?" -- Charles Darwin, Voyage of the Beagle (1839), Chapter V
Source:
http://home.att.net/~troybritain/articles/darwin_on_race.htm