You can easily change the default color scheme in Windows Terminal using its Settings. Access the Color schemes section present in the Settings and select any of the available color schemes.

You can only change the color set under the Light appearance. Google offers two color sets: classic, which will write the text of your event in black, or modern, which will write it in white.

Largely, the color change is stylistic ... opening your Brand Kit to find your brand's font choices, using pre-set heading ...