Top Alternatives to Color Cop

ShareX is an open source program that lets you take screenshots or screencasts of any selected area with a single key, save them in your clipboard, hard disk, etc

PicPick is an all-in-one program, primarily system tray-based, that provides a full-featured screen capture tool, an intuitive image editor, etc

Pixie is a utility made especially for webmasters and designers. It is a color picker with few extra goodies.

Gpick is an advanced color picker and palette editing tool.

Instant Eyedropper is a free color detection tool for webmasters that will identify and automatically paste to the clipboard the HTML color code of any pixel on the screen with just a single mouse click.

ColorPic is a color picker for windows.

gcolor2 is a simple color selector that was originally based on gcolor.