color for code

hex     #3b82f6
rgb     rgb(59, 130, 246)
hsl     hsl(217.2, 91.2%, 59.8%)

tailwind
~ blue-500 (#3b82f6) · arbitrary: bg-[#3b82f6]

css variables
--brand: #3b82f6;
color: var(--brand);
background: var(--brand);