Spur is an extension of the lip, arising from its base, hence almost in all the cases it is of the same colour of the lip or of a lighter/darker version. However, there are a few species that produce spur with unusually bright colour that is entirely different from that of the colouration of the lip and also of other flower parts.
This is a highly evolutionary method adopted by orchid plants to attract pollinators.
Post 34 – 30/November/2020