Any rule changes would have to have been made by a special resolution, requiring a super-majority at an AGM.
At the moment, an alternative rule made by the owners corporation under section 108 only takes effect on registration under the Land Titles (Unit Titles) Act 1970, section 27 or section 27A; or from any later date stated in the special resolution making the rule. Maybe you can search Land Titles records.
If the alternative rule was not lodged within 3 months after the day it was passed, the resolution is taken to have never been made.
In NSW, changing the external appearance of a unit requires the approval of a general meeting. The only reference I can find in ACT strata law is that a ‘rule’ can be made covering the external appearance.