Is there a way to enable a color picker like Sketch's in Illustrator? I really like the ability to drag the color slider while keeping my saturation/brightness consistent (this is just beneath the big color box in the screenshot below). If there is an option to do this kind of adjustment in Illustrator that's great too, but I can't seem to find it. Thanks!
There's no way to implement Sketch's color picker in Illustrator.
You can set the Color Panel in Illustrator to use HSB - Hue, Saturation, Brightness.
This allows for adjustments to Saturation or Brightness without altering the Hue.
Unfortunately the Color Panel has a tendency to switch back to the Document Color Mode (RGB/CMYK) as you work. So, at times, it's necessary to repeatedly reset the panel to HSB. Users have been asking for a fix for this for some time now.