Pelargonium magenteum flower colour competes strongly with other visual stimuli in the plant’s semi-arid habitat. Floral profusion during parts of winter and spring adds to domination of pollinator hearts and minds, or whatever body parts perform such functions in the hungry service providers of flowering plants.
Floral structure is another matter. Other pelargoniums of the south-westerly region of South Africa, plants with similar flowers in structure are often not as flamboyant in their blooming. Purple to magenta flower colours are possible from some of the mesembs in these parts, but the local vygies and a malvas are easily distinguished from each other, although the finer points of specific identification may be tricky.
When in search of P. magenteum in bloom, the Biedouw Valley is a good place to start. The photo was taken there (Manning, 2007; Manning and Goldblatt, 1997; iNaturalist).