A decision about common property is properly made by the owners corporation. You could propose that units owners be able to choose tiles for the balconies associated with their units with a price adjustment if their selection is more expensive. The owners at a general meeting might support your proposal or not. I would talk to an EC member about how it might be practically arranged without lumbering someone else with a lot of work. If you have EC support for a reasonable proposal I would expect a general meeting to support the idea.
In all this I am assuming that the tiles of a balcony are only visible from within the attached unit. If the tiles are visible more generally there might be a compelling argument for a consistent appearance to the building.