Paints and Renders
To finish off your thermal insulation system, or any system with a render finish on an external wall, you'll need high quality Facade paint. Facade paint needs a strong adhesion to the surface so the paint stays looking great and must be strong to resist damage from harsh weather, rain, sun, and frost.
Acrylic paints are very popular due to their low price and wide range of colours. They're considered the first choice as they do the job at the lowest price point. They form an elastic coating and are resistant to rainwater. They also have an average resistance to contamination and can be washed easily, including with a pressure washer. It's also possible to apply acrylic paint on old acrylic renders.
Acrylic paints have a relatively low vapour permeability and are therefore not suitable for insulation with mineral wool. They're also susceptible to algae development if left in shadowed areas, this can be somewhat mitigated with additives but full resistance can be achieved from silicate products.
Silicate paints are resistant to contamination, especially algae development. Surfaces painted with Silicate create a strongly alkaline substrate, so is a good choice in areas with lots of trees. They will also have good vapour permeability but lower resistance to water and rain impact. The paint should be applied in dry times and when the surface is not under strong sunlight. Wet stains on the facade should try very quickly without damaging the surface.
Siliate paints are, however, more expensive and have fewer colour options than acrylic.
Silicone paints have a unique resistance to water and contamination. Due to Silicone paints good vapour permeability and water resistance it can be applied to any type of insulation. Silicone paints are hydrophobic so water simply pearls on the surface rather than runs down it, washing the surface of contaminants.
Silicone paints are, however, relatively expensive. But the higher quality can be worth it. There are cheaper mixed options available, for example silicone-silicate, which still work very well and could be a more affordable option for you.