4x is great and has great potential, don't get me wrong, but i prefer 3x look.

Is there any tool to downgrade database? i don't have 3x database backup so that's not an option

Sorry, it is not possible to downgrade.

And it would be very silly for IPS to invest time and money in developing a tool to downgrade 4.x versions.

If the issue is simply the look then there are themes in the marketplace that emulate the old 3.x style