Hi,
Good day! My name is Santosh. I am Microsoft user like you. I will be glad to help you.
Please do right click on Desktop and click on Personalize. Click on colors and select custom in Choose your color section. Click on Dark under choose your default Windows mode. Scroll down and check the box "Start, taskbar and action center" under show accent color on the following surfaces section.
Please pick the color you like under choose your accent color section. You can choose color from there for taskbar.
I hope this information will help you. Please let me know if you need any further assistance.
Regards,
Santosh