v2.35.2:
https://codepen.io/Lexachoc/pen/MYgXpXM

v3.0.0-rc2:
https://codepen.io/Lexachoc/pen/EaYRWpV

Open these two examples, and hover the mouse over the modebar (don't click anything)

Note that in v2.35.2, the fill color of the icons changes when the mouse pointer hovers over them, which is correct.

In v3.0.0-rc2 however, the fill color of the icons WILL NOT change when the mouse pointer hovers over them, which is incorrect!