Believe it or not, yes. SCARLET, the first Anderson show to feature black characters in regular roles, was called both "politically incorrect" and "racist" by a handful of critics as the series prepared for its 1993 revival on BBC-2. The focus of the charges seemed to be the fact that the leader of the heroes was named "White" while the chief villain was named "Black", which was said to be yet another example of perpetuating ethnic stereotypes of black being bad and white being good.
The only problem with this argument being directed at SCARLET was that it simply didn't apply. The villainous Captain Black is caucasian, while the black characters, African-American pilot Melody Angel and West Indian communications specialist Lieutenant Green, are heroic figures and play prominent roles in several episodes. The inclusion of black characters in significant roles was no accident, according to Gerry Anderson, who in a 1992 interview said that he had tried as far back as 1961's SUPERCAR to incorporate black characters into his shows but was rejected by ITC due to possible problems getting the shows syndicated; SCARLET was the first show in which he was actually able to get them accepted by ITC.
Interestingly, except for its recent U.S. run, this argument has seldom been raised about THUNDERBIRDS, which consistently perpetuates negative Asian and female stereotypes in chief villain The Hood, Jeff Tracy's manservant Kyrano, and Kyrano's underutilized (except as weepy damsel-in-distress) daughter Tintin, and outside of the three Asians and Lady Penelope features no minorities in significant roles. Contrast this to SCARLET, with five female regulars, women in significant heroic and villainous guest roles, and the prominent presence of Lieutenant Green, and the charges of political incorrectness and racism become even more ludicrous.