Certainly not a racist, as Siva touts non-attachment to physical form as a primary step in attaining moksa, and in fact has His own dark skinned forms, specifically Bhairava.
In His wisdom Siva knew that Parvati would have need to be Kali Ma, as well as Durga (Who Herself has at least a few dark skinned forms). It has also occurred to me that by Siva calling His Consort Kali Ma, Mahadeva (Great God) Siva was also, in fact, endeavoring to defray potential racism amongst the people, as Kali Ma is almost certainly the most worshiped form of Parvati, granting a high status to the "Black Mama" in Indian society in general, and these days globally. Shiva is almost only ever shown in intimate circumstances with Kali Ma, as presented in sacred murtis, indicating clearly enough Shiva did not have any aversion to this form of His Consort and Beloved.
In fact, the multiplication of forms thus, as Kali Ma and Gauri, has certainly elevated the status of the "black mama" generally in society, from Hindu to the world, as yoga and Vedanta and other mediums have very much broadened reverence for the Dark Mother of the Universe in today's popular culture and society generally. Great God Siva certainly knew this as He touched on His Beloved's slight insecurity, the which She certainly knew, at some level, why She felt, i.e., as a means of Divine transformation. Shiva's slight toying with Parvati's insecurities (something Shiva is very much known for as a means to help others surpass attachments) was designed, in the Mind of the Eternal, sat cit ananda, to grant the children to come a means to deal with a likely foible or shortcoming endemic to the Kali Yuga, the propensity towards dualistic thinking and prejudice, us vs. them dichotomies and so forth.
In it's more ancient and properly practiced form, the caste system is also designed to defray divisions in society by creating social divisions that are by their nature clearly dependent upon one another, as they are divisions of labor (as opposed to other potential designations of group formation) that did not have aught to do with color, at least ideally.
Lastly, I might and ought note that Krishna, the most popular and many argue most important Avatar of Vishnu (God the Maintainer), means "black" in Sanskrit. The obvious statements made to a world wrestling with issues of racism thus would be, God and Goddess are often Black, therefore we ought to recognize the Divine in others regardless of their colors !!!!!