Add more contextual css variables for more css customization control

[hexaltation]

In some components color palette variables are used directly instead of rewrapping it in more contextual variables.

For example, ACLs use --grist-color-light-green directly and therefore is overwritten when changing this color value in custom.css. While we may want to keep the green in this case.

Original

With custom CSS redefining --grist-color-light-green

May be we can add more contextual variables for more control in css customization and less side effects.