Is there any way to bring back old EC square gui without new stylizations? I know there was texture pack for this when they changed gui with that "old style" theme several years ago but I can't find it now.
Yep, that was a good and lean UI. When the new UI hit the client, my framerate went to nuts. Luckily I had saved a copy of the old UI, so I started running my own personal UI based on that code.
Here is my old copy:
Uploadfiles.io - DefOld.zip
It has the old textures like this..
And the yellowish icon style:
But I think those assets are pulled from the UOP files anyway(?). I'm personally just sticking with the textures that come with the client, so my UI changed from the gold to blue as well.
There is nothing ready to use I fear. The old UI is not ready for things like the new trade window (i.e. platinums) and a couple more of the newer stuff. And there are also some real improvements in the new Default, like the cool new spellbooks from Pinco.
If your are not in the position of making you own changes to the UI, I fear you are out of luck with this. There is no simple drop-in replacement that I know of.