How to change the icon colors of the mobile bottom menu
To change icon colors mobile bottom menu (such as: cart icon, user account icon,...):
There are two ways to do that:
1. the first is to edit from the theme's css file and re-deploy the content
2. the second is to use custom styles in the backend. (STORES > Configuration > [MAGE SOLUTION] Front-end Builder > Font & Style > Custom style).
Both ways add the following lines of code:
.header-mobile-tabs--bottom li button .icon-cart-top{color:#your_color_code}
.header-mobile-tabs--bottom li button .icon-my-account{color:#your_color_code}
Please remember change #your_color_code to RGB color code (eg: #ff0000)