Actually from my short testing. The color for the secondary clock font is from your "taskbar" button text color. Not Start button text color. To make sure the secondary clock have same color of your primary clock text color. You will need to set all your taskbar button "States" to that color. All States which mean Normal, Pressed, Highlighted, Activated, activated hilighted etc etc.
Note: I tested on WB11 on Win10 OS. Not sure if the same on WB11 on Win11 OS.
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