Ignoring the fact most of these plants wouldn’t survive outdoors in the UK, here are some ideas for funky, colourful Sicily-style plant presentation. All photos taken around the beautiful, tiny island of Ortigia, Sicily in August 2018.
Here are some potentially useful links, which make me realise there is more effort required than merely painting, but it’s still do-able for someone as slow to get around to things that require purchases and faff as me:
WikiHow on how to prepare, paint and seal a terracotta pot.
There is also Favecrafts, which even has a shortcut suggestion.
Fine Gardening magazine also has some good suggestions, eg a foam brush.