Add ability to type in numbered values to colours / positions / YPR#808

Instead of trying to be precise with sliders, the ability to manually put in values would save a lot of minor annoyance with trying to get things exactly right. It also allows for consistent colour use and codes outside of just global colours.

I second this.

Clicking directly on the sliders results in unseen decimals that meddle with perfect symmetry, for example. And am hence forced to click the arrows 90 times for a perfect 90° rotation.