Enter a hex color, drag the opacity slider to set alpha, preview the transparency, and copy the rgba() string.
Split the hex into red, green and blue pairs, convert each to 0–255, then add your chosen alpha value to form rgba().
Alpha ranges from 0 (invisible) to 1 (solid). 0.5 is half-transparent; pick the value that matches your design.
Yes — 3-digit shorthand like #f00 is expanded to #ff0000 before the rgba() value is produced.