source: https://www.color-meanings.com/
purple (homura): symbolizes spirituality, mystery, royalty, and imagination. its positive aspects include compassion, fantasy, wisdom, and creativity, meanwhile its negative aspects include sensitivity, vigilance, immaturity, and emotional outbursts.
yellow (mami): symbolizes happiness, optimism, positivity, and intellect. its positive aspects include creativity, perception, mentality, and warmth, meanwhile its negative aspects include cowardice, deception, egotism, and caution.
red (kyoko): symbolizes action, strength, energy, and passion. its positive aspects include sexuality, courage, desire, and confidence, meanwhile its negative aspects include anger, danger, revenge, and aggression.
blue (sayaka): symbolizes security, trust, loyalty, and responsibility. its positive aspects include confidence, peace, honesty, and reliability, meanwhile its negative aspects include conservativity, a passive mindset, depression, and predicatibility.
pink (madoka): symbolizes compassion, love, femininity, and playfulness. its positive aspects include kindness, warmth, romance, and intuition, meanwhile its negative aspects include emotional outbursts, timidness, immaturity, and a lack of confidence.
orange (nagisa): symbolizes emotion, youth, optimism, and enthusiasm. its positive aspects include spontaneity, creativity, warmth, and positivity, meanwhile its negative aspects include wanting attention, superficialness, impatience, and domination.
pretty accurate, although nagisa's is a bit less, probably because she has more than one theme color