Algodoo

firstly, don't look into the hue of the triangle YET, it'll ruin the quiz,
NOW, put the triangle-with-an-unkown-hue onto one of the dots based on where the closer the triangle is to some other fixed triangle (blue, purple, white)
the closer you think the unknown-hue is to the said fixed triangle, you may also comment the color of the dot you put the triangle on (which surprisignly (:o), isn't mandatory (also for the glowing dot on the bottom right of all the dots, its name (not color, it doesn't officially have one) is the glowing orb of destruction, depression, and damage)), and if you check the hue of the triangle after, you may be surprised!