Core isColorOverridenSyncIfNot should use this.internalStyle not this.style

[WebCoder49]

So doesn't change style attribute from the outside; the docs say the style attribute shouldn't be changed from the outside.

[WebCoder49]

This is true for the --code-input_ variables but cannot be true for the transition properties since it needs to disable user-set transitions for a few frames (otherwise invisible to external code) to check if color and caret-color properties are overridden.

[WebCoder49]

Fixed in #209