The current plots for "builds divided by chroots" are pretty hard to read right now: too many (meaningless) colors, and labels are just one after the other. One quick and easy improvement would be to:

• put bars horizontally, with well-placed labels;
• assign meaningful colors per distribution.

Something like this:

In this vertical format, you can put together the two of them: last 24 hours and last 90 days. And then you can remove the tooltip (the table that shows up when the pointer is on top).