Palettator is a floating panel and you can put stuff in it and sample colors. Simple as that.
Place your palette, reference or your cat there. The panel is visible in fullscreen mode, floats above documents. Toggle visibility with hotkey, export dominate colors to swatches.
⚠️ This version will NOT work in PS CS6 and below. Note that currently native version of Photoshop for M1 Macs isn't supported.
You can also join my Discord if you have any suggestions or questions.