Yeah I looked up a pic of Madaras susanoo and it is blue
One of the big points of the show is Yin/Yang Light/Dark
Naruto has alot of the energy from his parents whom where Yellow and Red. Yell, Orange, and Red are very warm colors so I'd put them in the Light catogory.
The blues and purple are cooler so I'd say there are in the dark category ( green is a neautral color btw).
The Older son was of the dark so anything blue and purple comes from the same place. So Madara, Orochimaro, and Sasuke all come from the dark. What the difference is that Sasuke is more similar to the Older bro since he has the same color as him.
Same with on the Light Younger Son side. Jiraiya, Hiruzen, Hashirama, Minato, Naruto's Mom.. they all come from the light and have warm energies like the Younger Son, but Naruto comes from the same part of the Light spectrum that Ashura came from.