It does look like they missed the table title color. One thing you can do while waiting for the bug to be fixed is set the "paragraph" color (the background color) of the title to the same as the background color. It will retain that background color.
- Click on the title
- In the format sidebar click on Layout
- Change the "paragraph background" to the desired color
As I mess around with all this formatting, I am noticing a whole host of bugs. The title does not, by default, center vertically in the "paragraph background". A "full" border around the title does not have sides on it and will only be the upper line unless other changes are made. Borders on the title don't line up correctly to the table either on the sheet or when printed or both. Charts have numerous problems with the "don't print background" setting. The list of bugs I found in the last 30 minutes made for a very long post, so I deleted it. There have already been numerous formatting and printing bugs mentioned in the past that have not been fixed and probably never will. I wouldn't count on any of these new ones to be fixed so why bother reporting them.
Apple needs to put a team full time on fixing all these formatting bugs, as well as the computational/formula bugs that they have ignored (some of them for years). It is embarrassing and far far below the standard that Apple claims to set. I don't care that Numbers doesn't do all that Excel does but what it does do it should do correctly.