Green leaf colours in a suburban Australian hotspot: Colour differences exist between exotic trees from far afield compared with local species

• Leaf colour of endemics and exotics were compared in a global hotspot.
• Australian endemics were greyer, less chromatic, and darker than exotics.
• Colour changes might occur with planting exotics from far afield.
• Due to the genetic isolation of Australian plants, colour impacts may be greater.
• Colour is a component of homogenisation with urbanisation.

Endemic species are often replaced by plantings from non-local areas in new suburbs in the developed world. Does this lead to colour changes? This paper compares colour in the leaves of exotic trees planted in suburbs to that of endemics in the Southwest Australian Floristic Region. Colour in plant parts was assessed by the Natural Colour System of Sweden, which enabled quantitative comparison between species. Hue, chromaticness, percentage yellow, blackness, whiteness, luminescence, and visual lightness were determined. The leaves of Australian trees were less chromatic and darker than exotic trees, suggesting that colour changes are occurring with suburbanisation in this region.