The owners corporation will have authority to select tiles as they are considered common property. They should select tiles to match as close as possible. The quote they have approved for the works should specify this.
If you wish to have different tiles, then offer to pay the difference in price. It is unlikely there will be any objection from the other owners.
BTW – if you want to insist on access via scaffold on the outside you could also offer to pay for the scaffold hire but this is likely to be more expensive than the tiling works.