Uncle Tom is racist and derogatory :
Uncle Tom
n
informal derogatory a Black person whose behaviour towards White people is regarded as obsequious and servile
[C20: after the slave who is the main character of H.B. Stowe's novel Uncle Tom's Cabin (1852)]
Uncle Tomism n
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014