I'm also very fond of colored pencils. They are great to enhance oil pastels with scraffito details, whereby the underlying scratch mark is colored more vividly than scratching alone. I love watercolor pencils, too. So versatile! The nice thing with them is, the sketch dissolves and no pencil marks show through a finished watercolor, ever.

Yes, there are artists who work purely with colored pencils; many of them in the realm of photorealism. Colored pencils are unbeatable on velour paper like Pastelmat. Unfortunately, it's A LOT of work to color a larger format, even a 30x40. Also, if one uses archival quality pencils, it's EXPENSIVE.

Have a look at her work:
https://www.youtube.com/@KirstyPartridgeArt/videos