Color spaces should be defined by ColorSpace objects

[LeaVerou]

Currently Color spaces are defined by object literals.
In the Color API we used ColorSpace objects. There might be value in using such objects here as well, e.g. the ability to create anonymous color spaces that aren't available globally via ids. It will also make typings easier I suppose.

[svgeesus]

Although those objects currently have:

readonly attribute CSSOMString? iccProfile;

and see #45

[LeaVerou]

Yeah, ours wouldn't have that attribute (yet). 🤷🏽‍♀️