Modern CSS :root { --mainColor: #12345678; } body { color: var(--mainColor); font-family: system-ui; } a { color: rgb(0 0 100% / 90%); &:hover { color: rebeccapurple; } > span { color: color-mix(in oklch, cyan, green 25%); } } :is(input, button):is(:hover, :focus) { color: oklch(40% 0.268735435 34.568626); } Becomes... :root { --mainColor: rgba(18,52,86,0.47059); } body { color: rgba(18,52,86,0.47