Removal of RED numbering for too low settings in Flushing volumes?

So back in the settings in 1.10.2, When you went to adjust the flushing volume settings, if it was too low between colors and would cause a blend issue, it would show those in RED so you would know to up the settings. I would adjust them till all where black again. I do this to try and lower filament waste.

Now no matter how low you go, it no longer will turn red the ones that would be too low a purge level. They all stay black. Why was this removed?

Some color combos I would keep it as low as .35 and no issues, but now I am unsure. I think this setting needs to return the way it was.

So how can I now tell if the purge is set too low without having to print??