[Bug] Colorpicker does not support modern rgb color syntax

[setyb]

Bug Report

Bug Description

The Stylus colorpicker does not currently support modern rgb color syntax. It only supports the old legacy syntax.

For syntax details, please see:

CSS Color Module Level 4
https://drafts.csswg.org/css-color/#typedef-modern-rgb-syntax

and

rgb() - CSS: Cascading Style Sheets | MDN
https://developer.mozilla.org/docs/Web/CSS/color_value/rgb

System Information

• OS: Linux
• Browser: Firefox 113.0.2
• Stylus Version: 1.5.33

[tophf]

The modern syntax is supported, but only as an input. We should preserve it in the output as well and add an option to switch the output.