Updating custom.css for style modifications

[anjaliagarwal8]

Hello, Thank you for building such a beautiful and unique website template. I loved organizing my data in this template.
I wanted to make some modifications though related to font color and size and I have seen that I have to update the custom.css file for that. But I am not able to see any modifications in the original website. Can someone help on how to update the custom.css file to change the font color?

Thank you