Preamble
At Domopalooza, the first time (of several) I heard a new feature announced as "the most requested feature on the Domo community forum", I assumed it was the one I will propose. In fact, I hope to prove to you that this is the most requested feature, and the next time anyone tries to apply that title to a different feature, then I implore you to gently correct them that anything besides this feature can, at best, be the second-most requested feature.
For example, if someone says, "Announcing the GA release of the most requested feature in Domo! Dark Mode!"
You could say, "I hate to interrupt, but that is not the most requested feature."
The feature I am proposing gets asked about in different ways, but they all boil down to the same thing. Recently, there are some people that want to add scrolling to HTML tables, since they've been using HTML tags to apply conditional color formatting. The answer that gets is that the HTML table is about to be retired. That's fine, I don't like the HTML table, anyways. Other people request "conditional formatting" or "applying color rules based on a different column".
The way I would implement this is in the pivot table, which is way more flexible in handling data than the HTML table.
Proposal
In addition to Rows/Columns/Values, add an option for a "Series" or "Color" that could be used to apply color rules by cell, just like the "Series" in a bar graph.