Chromium browsers
Chrome and Edge usually expose the most complete set of display timing and media query signals, though settings and power modes still matter.
Safari
Safari can expose strong colour signals on Apple displays, but some APIs behave differently from Chromium.
Firefox
Firefox is useful for comparison, but colour, HDR, and timing behaviour can differ by operating system.
If results differ
Run Pixy in more than one browser before assuming the display is wrong. Differences often reveal browser support, OS display mode, cable limits, mirroring, or power settings.