Orchard Core CMS has a number of built-in TextField editors: Standard, Multi-line, Icon Picker, and Predefined List. I was curious what it took to develop a custom text editor so I spent a couple of hours at Starbucks this past weekend developing a custom Color Picker for Orchard Core CMS.
When adding a TextField to a Content Type one can choose Color Picker as the editor. The Color Picker offers a default value setting where one can set the default color to be displayed for the field.
Here is what it looks like to add a Color Picker TextField to the Page Content Type with the color set to green.
The custom editor uses the Spectrum jQuery Color Picker to choose and display colors. I didn't pick it for any particular reason. By default the color picker looks as follows.
One could certainly change the UI as well as add additional editor settings to drive a more custom look and feel. One could also completely replace the chosen jQuery Color Picker and even use the browser's built-in color picker.