Provided default values for when user set's nil as color for tab bar items.

[mohpor]

Regarding #860 , #904
This solves the problem of overridden prepare() functions and you can set tabItemsNormalTitleColor and tabItemsSelectedTitleColor at any time.

[daniel-jonathan]

Looks good :)

[daniel-jonathan]

I removed this merge and the other ones prior in relation to this. The fix doesn't consider images.

[mohpor]

Could've built on these, but ok.

[daniel-jonathan]

Yes and no. There are properties now that will need to be maintained, and I think it would be better to do something like this:

tabBar.setColor(.blue, for: .selected)

This would completely abstract any specific attribute this is set for (images, text) and removes the management of the properties internally.

[daniel-jonathan]

Please find this feature available in the latest Material 2.12.0 release.

Example:

tabBar.setColor(Color.grey.base, for: .normal)
tabBar.setColor(Color.blue.base, for: .selected)

Thank you @mohpor for the initial version, it really helped with laying down the groundwork :)