MacOS Color Filters don't work on all displays -- anyone else seen this?

I have been setting up MacOS color filters via "System Preferences" -> "Accessibility" -> "Display" -> "Color Filters". When I set it up, the filter effect only shows up on two of the four monitors I have attached to my Mac Pro. (The two that work are a Samsung LC49G95T and a Dell S3221QS; the two that do not are both HP2509s.)

I have filed a bug report with Apple on this, but it occurs to me that it might be helpful to add to it any other users' experiences with monitors that do and do not "work" with color filters. Has anyone else seen this phenomenon?

Alternatively, does anyone have any suggestions for getting the 2509s to show the filtering?