A German company has used biomimicry of a lotus leaf to produce an exterior paint which essentially repels water. This means dirt, mould, mildew and other microorganisms can't secure the nutrients they need to survive. In addition, the colour remains vibrant, there is no need for any chemical treatments and repainting requirements are reduced.
https://www.stocorp.com/sto_products/stocolor-lotusan-low-voc/