I don't know what was your default settings but taking cue from my computer, you can try following settings and let me know whether it works for you
Windows Key+I to invoke Settings > Personalization > Colors
- Uncheck Automatically pick an accent color from my background
- Remove any custom color
- Transparency Effects - ON
- Uncheck both options under Show accent color on the following surfaces
- Choose your default app mode - Light
Click High Contrast Themes > Under Color & high contrast
- Apply color filter - Off
- High Contrast Theme - None
Under Themes - See whether you got the right theme or not