Kelir

Kelir can help you select the desired color from any part of the screen. In this respect, it works like a color picker allowing the user to preview the chosen color.

What is more, the tool can also generate color palettes from a given picture or your color selection.

The application is very unobtrusive, which means it will not interfere with your normal workflow in any way. Besides, it runs from the Menu Bar, so it can be accessed any time you need it. I am sure you will not have any difficulty to use the color picker feature. What makes it more useful is that it allows you to choose a color different from the one you initially picked. In this respect, you can decide to use shade, tint, analogous, triadic and complimentary colors. Finally, once chosen, the color code is automatically stored in the clipboard, ready to be pasted to other applications.

Good news is that Kelir supports generating a wide range of color code types, including Hexa, Android RGB, Android ARGB, Android XML, UIColor RGB and HSB, NSColor RGB and HSB, NSColor Calibrated RGB and HSB as well as NSColor Device RGB and HSB. This makes the resulting code compatible with multiple applications and programming languages.

The standard version of Kelir has some drawbacks, most of them related with not supporting collaboration with other devices and users. For instance, it does not allow syncing your color preferences on your iCloud account. Likewise, you cannot view colors or explore palettes created by other uses of Kelir. Moreover, it is a shame that it does not create gradients.

In short, Kelir comes in very handy when you need to work with specific ranges of colors. In this regard, you can use it to make sure your using exactly the same color you intend. The product is available from the Mac App Store at no cost. However, some of the limitations mentioned above can be avoided by acquiring the Pro version as an in-app purchase.