I would say americans perhaps are less racistic inside USA, since theyre all are immigrants. All americans who are not natives would be quite arrogant if they thought they had more rights as immigrants than immigrants from other countries than where they come from.
But in my impression americans have less respect for the lives of the people in other nations than america. Usually americans have a different approach than other nations when theres international conflicts. They bomb like it should be a total war, to save their own soldiers, not caring about tens of thousands, or millions of innocent civilians die. America is quite often on the war-path, while european nations try to stay away, but the americans nag and demand they also join as allies. I think thats quite racistic. To think yourself has the right to control other nations with different races, kill people, and hang their leaders, is very racistic. Of course, europe had Hitler, i guess he gives us quite many racist-points, but on the other hand, all europe hate hitler, and try to have an attitude to racism opposite of what Hitler had.
Another thing is europe consist of many VERY different nations. Everything from Iceland to Turkey, from Spain to Russia. You compare one nation to an entire continent which have a broad specter of culture. Then i mean official national cultures who influence the government, not that you have a street with different ethnical families, which still have the same governmental structure and national culture.
Europe still lives on ancient land, still suffering from old disputes about land, religion and culture, while the americans dont since they just took an entire continent from another race and got a fresh start.