I think this question is pretty flawed - I'm not sure if "subtle" racism is less real, deliberate or damaging than "deliberate" racism, and I'm not sure those categories really are mutually exclusive to begin with. Institutional racism doesn't exactly operate like that.

However, you might find a lot to turn over in the Jim Crow Museum's discussion of Amos 'n' Andy, a very popular TV show that came from a radio show... that emerged out of the minstrel show tradition.

It was the first show to have an all-African American cast, and was possibly the first situation comedy, full stop.

What can make Amos 'n' Andy complicated to discuss is that (if you include the radio show) it had a very long run, and it was especially subject to subversive readings and the kind of detournement you see in, for instance, old jazz covers of show tunes. It lends itself to irony.

From the Mark Freeman response linked there, on the one hand:

Henry Louis Gates recounts that "One of my favorite pastimes is screening episodes of Amos 'n' Andy for black friends who think that the series was both socially offensive and politically detrimental." ... He assets that, "The performance of those great black actors ... transformed racist stereotypes into authentic black humor." The historian Thomas Cripps suggests that only the main characters are stereotyped by language and dress. He points to many examples of well-dressed, supporting actors speaking in Yankee accents. (In fact there were Black professionals including a doctor, a minister, a teacher, a detective, a real estate broker and a nurse.)

... and on the other hand:

In response to NAACP protests about the TV show, a survey by Advertest (sponsored by the network) claimed that 75 percent of the 365 blacks interviewed disagreed with the proposition that Amos 'n' Andy reinforced stereotypes. The program's premiere coincided with the NAACP's 1951 Congress and was viewed by the delegates assembled. Organizing received a head start from this circumstance. This is how the NAACP characterized its objections to the show:

1. It tends to strengthen the conclusion among uniformed and prejudiced people that Negroes are inferior, lazy, dumb and dishonest.

2. Every character in this show with an all negro cast is either a clown or a crook.

3. Negro doctors are shown as quacks and thieves.

4. Negro lawyers are shown a slippery cowards, ignorant of their profession and without ethics.

5. Negro women are shown as cackling screaming shrews, in big-mouthed close-ups using street slang just short of vulgarity.

6. All Negroes are shown as dodging work of any kind.

7. Millions of white Americans see this Amos 'n' Andy picture and think the entire race is the same.

Either way, it was a show based on stereotypical depictions that weren't flattering, were racially essentialist, and were shaped by creators of one race for an audience of the same race - that wasn't the one being depicted.

One last bit from Freeman:

Lillian Rudolph who played Madame Queen, Andy's girlfriend on the tv series, spent three months studying with a white vocal coach so that she could master the "minstrel style black dialects" (A&J p., 35). And Godsen himself coached the black male actors. He maintained that as the creator of the series he "ought to know how Amos and Andy should talk." Spencer Williams -- Andy in the TV series -- had been an director of independent black films. He replied to Godsen that I "ought to know how Negroes talk, having been one all my life" (Clayton, Ebony in Fife p. 9). What we have is "a white man teaching a negro how to act like a white man acting like a negro" (A&J p., 35).

If you're curious what this was really like on screen, there's at least one episode on YouTube.

The exclusion of the North America's indigenous peoples regularly included as main characters in TV shows is a pretty glaring problem. This is especially problematic since the biggest example of Native Americans in American TV is Bonanza, where their indigenous characters were horribly stereotyped and regularly played by non-indigenous actors. One of the few examples of good representation - Adam Beach's character on Law & Order: SVU was an exception, but far from the norm of exclusion and whitewashing.