HEX code for Transparent or No Color needs to be available within visuals

Many visuals formatting color only allow selection from the HEX code color palette, yet many I have seen already contain the white box with the red slash for no color, but if this is ever changed it cannot be changed back or re-selected to have no color. The codes I have seen for transparent are 8 characters which HEX only allows 6 - dropping the alpha required to code transparent. Please add the no color or transparent option to this palette since customization of the color is not always allowed. Or add the slider for transparency to all color options within visuals.