List View colors

[jameskoster]

Now that we're exploring the colorisation of special blocks like Template Parts and Reusable Blocks (PR: #45473), it might be time to evaluate how we style blocks in List View.

If we simply perpetuate the existing principles we get the following which feels a little heavy-handed:

In the first column there is some visual tension between the fully-filled selected Group block and the purple template part beneath.

There's a needle to thread in making the colorisation clear and useful, while not launching a visual assault on the eyeballs.

One idea would be to only colorise the text / icon, and lighten the background on selected blocks so that we don't need to use white text. It also means we can use the same background treatment regardless of block type:

This looks more harmonious to my eye, but I'm keen to hear thoughts and feedback.

[jameskoster]

After a huddle with Joen this may no longer require discussion :) See: #45473 (comment)