[css-color-4] Add <alpha-value> parameter to <named-color> and <hex-color> #10678
Description
Problem
Currently, you have to specify the alpha-value separately in <named-color> and <hex-color> as opacity. It affects all elements if there are multiple.
.element {
background-color: #aaaaaa;
color: black;
opacity: 0.5;
}
Proposed Solution
Add an alpha-value to <named-color> and <hex-color> in the same line:
.element {
background-color: #aaaaaa 0.5;
color: black 0.7;
}