Why doesn’t a palette extracted from a photo look like a "harmonious" color scheme?
Because the algorithm answers "which colors dominate this image by pixel count", not "which colors look good together"; a sunset photo returns several close shades of orange, because that is genuinely what dominates the image, not a palette curated by a human.
How many colors can this tool extract from an image?
Up to 16 swatches per extraction; the median-cut algorithm splits pixel boxes until it reaches the requested count or that cap, whichever comes first.
Why do two similar photos produce palettes with slightly different colors?
Because the modal color is computed over a 4096-bucket grid (4 bits per channel): a pixel that falls just past a bucket boundary changes which bucket is the most frequent in the box, and the final color shifts along with it.
Does a PNG's transparent background color end up in the extracted palette?
No: pixels with an alpha value below 16 are discarded before any calculation, so only the visible pixels of the image contribute to the extracted colors.