Canvas returns four bytes: red, green, blue and alpha, each from 0 to 255. PixelPick keeps those integers authoritative. Opaque HEX writes two uppercase digits per RGB channel. When alpha is below 255, a fourth pair is appended as #RRGGBBAA. RGB output uses the three integers; transparent output uses rgba with alpha divided by 255 and rounded to three decimal places.
HSL derives from the same RGB channels
RGB channels are normalized to 0..1. Lightness is the midpoint of the largest and smallest channel. Saturation depends on their distance and lightness; hue follows the channel holding the maximum. PixelPick rounds hue to a whole degree and saturation and lightness to whole percentages. Alpha is shown separately and never composited over white or black before conversion.
One alpha-aware conversion
For decoded RGBA 51, 102, 153, 85, HEX is #33669955. RGB channels are rgb(51, 102, 153); the alpha-aware CSS form is rgba(51, 102, 153, 0.333). HSL is hsl(210, 50%, 40%) and the alpha-aware form is hsla(210, 50%, 40%, 0.333). A viewer may show a different final color depending on the background beneath that semitransparent pixel.
Know what the value describes
PixelPick reports the RGBA bytes produced after this browser decodes the file into Canvas. Embedded profiles, browser conversion and display characteristics can make those bytes differ from another workflow. Use the result for ordinary digital design inspection, then verify important brand or production colors in their authoritative source. It is not calibrated colorimetry, physical paint matching, medical interpretation, accessibility certification or a safety measurement.