Allow specifying initial colorspace the picker opens to

Regardless of the format the color is currently in, initially show the picker in the specified format.

Example: color value is `#000` and the picker should open in HSL

cc @meodai

Start at the color picker entry point and trace how the initial color format is selected when the picker opens. Verify the behavior with the issue's example, where #000 opens in HSL, and ensure the specified format takes precedence over the color's current format.

Written by the indexing model from the issue text.