Color picker option

Uploading correct patch file.

+++ b/src/Plugin/LayoutOption/StyleAttributeColor.php
@@ -0,0 +1,94 @@
+    return $this->processAttributeOptionBuild('style', $regions, $build, $region, $style);

The problem with setting the "style" attribute is that it does not allow other plugin to act on it. processAttributeOptionBuild() would have to be updated to concatenate potential other options.

Also I am not sure this is something we want to handle, that's why I am assigning to @pdureau. Theorically in design systems, we want to set CSS classes that then apply the CSS properties.

There is are still a tricky things to handle beside, in HTML5 color input there is no way to unset the value, and default value is black.
One more thing I want to do is to be able to add opacity for the color option,