Color Cop is described as 'Multi-purpose color picker for web designers and programmers. It features an eyedropper, magnifier, variable magnification levels, 3 by 3 and 5 by 5 average sampling, snap to websafe, color history, and a 42 color complementary palette' and is a Color Picker tool in the photos & graphics category. There are more than 50 alternatives to Color Cop for a variety of platforms, including Windows, Mac, Linux, Web-based and Flathub apps. The best Color Cop alternative is PicPick. It's not free, so if you're looking for a free alternative, you could try PicPick or Just Color Picker. Other great apps like Color Cop are Realtime Colors, Instant Eyedropper, Sip and Pika.
this one is really twin of ColorCop