A photo may contain millions of distinct RGB triples because of texture, antialiasing, noise and compression. Listing exact frequencies would produce many nearly identical swatches. PixelPick samples at most 40,000 evenly strided source pixels and groups each RGB channel by its upper four bits. That creates at most 4,096 coarse buckets and keeps palette work bounded on large images.
Buckets are ranked deterministically
Fully transparent pixels are ignored. Every other sampled pixel increments one bucket while its original RGB channels are accumulated. The displayed swatch is the rounded mean of those original channels, not the bucket corner. Buckets sort by count descending and numeric key ascending, so the same decoded pixels and dimensions produce the same eight outputs. The percentage describes sampled pixels, not an exact full-image census.
Frequent does not mean visually important
A large neutral background can occupy most buckets while a small accent defines the design. Quantization can also merge close tones and separate colors that lie across a bucket boundary. Treat the palette as a fast starting point: click exact accent pixels, save the values that matter, and review them in context. PixelPick deliberately avoids calling the result AI, dominant semantics, harmony or a certified brand palette.
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.