The brand I work for has multiple branches with their own colors, each color containing 8 different hues. I created a color style for each color and use them when creating designs. 

Sometimes I need to play around with the colors to find the correct hue, but this can be very frustrating due to the fact that when I click ‘Fill → Library → select my color’ the menu immidiatly closes. If I have to do that 8 times to find the right hue + circle back to the best options that means I have to click at least 18 times. But if the menu would stay open I could do it within 9 clicks. 
This might not seem like much at a glance, but when you have over 25 shapes/text blocks on a page that need color that means I have to do 450 clicks instead of 225.

I can see how the menu staying open is not helpful in everybody's usercase, but having a toggle somewhere where I can choose whether I want this menu to stay after a selection would be very helpful and save me a lot of clicks.

TLDR; When selecting a pre-set color style for a shape or text, keep the menu in the screen to easily test out different colors.