[FIX] web, web_editor: customize colorpicker inputs from web_editor

Styles for the hex and rgba inputs from the color picker were modified
on directly from the web module, which means that for a specification
concerning only the frontend colorpicker, the backend colorpicker was
also changed.

This commit reverts the changes that were made and only applies the new
style for the website editor.

Related to https://github.com/odoo/odoo/pull/65249



closes odoo/odoo#67396

X-original-commit: 9529e296
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>