The red dot on Discord icon can be disabled by turning off notifications. Here is how you can do it: Open Discord and click on the Gear icon to open User Settings .

Well, Google just reverted the change, as the red Gmail notification icon is back. The red Gmail notification icon is back Gmail version 2023.06.11x has started rolling out, and it reverts the change.

Red has been dropped again, but Dynamic Color is not implemented in its place. After version 2023.11.26.x, Gmail’s notification icon no longer has a red background.