My reading of various parts of the Act is that, if it would be a radical change to the appearance of the common property, it would require a special resolution (75 per cent in favour) at a general meeting under section 108 (below)
If it’s just a bit of a spruce-up and the addition of a painting or two it could be passed by the committee.
(1) Procedure for authorising changes to common property
An owners corporation or an owner of a lot in a strata scheme may add to the common property, alter the common property or erect a new structure on common property for the purpose of improving or enhancing the common property.
(2) Any such action may be taken by the owners corporation or owner only if a special resolution has first been passed by the owners corporation that specifically authorises the taking of the particular action proposed.