Blossom has long orange hair with triangular part and bangs, pink eyes, and wears a pink dress with a red bow on the top of her head and a heart-shaped hairclip when seen from behind. As the smartest one and the self-proclaimed leader of the Powerpuff Girls, she is often seen as the most mature, level-headed and composed member of the group, although she can also be fussy, overbearing, vain, and overly analytical at times. She tends to "mother" Bubbles and Buttercup, and often tries to play peacemaker between the two if they fight but ironically she is quick to argue with Buttercup who acts on impulse as opposed to her analytical nature. She is naturally caring to mainly her sisters, but also the Professor as well. In one episode, "A Very Special Blossom", we are shown a darker side to Blossom, when she resorted to looting.
Blossom is shown to lavish intellect-enhancing toys and is often seen, in her free time, curled up with a good book. In the episode "Power-Noia" Blossom once had nightmares that she didn't study for an upcoming test due to saving lives all day. This possibly means that Blossom is the smartest student in Ms. Keane's class.
She's also the one behind the strategies and plans that the Girls themselves often use in battle. In the episode "Mime For A Change, " she can play rock guitar. After the girls were created in The Powerpuff Girls Movie, Professor named her Blossom for speaking freely and honesty to him, and for being the first to speak (especially to him). Her personality ingredient is "everything nice", and her signature color is pink.