Colorful, playful, joyful. The art of Niki de Saint Phalle (1930–2002) and Yayoi Kusama, now 96, comes together in the exhibition “Inner Child,” a title that points to a state of innocence. The show includes Saint Phalle’s Last Night I Had A Dream, an 18-piece wall installation made up of several sculptures evoking youthful creativity and curiosity. Paintings from Kusama’s “Infinity Nets” series are inspired by hallucinations she had as a child. As young artists, both women turned their back on establishment norms and sought spontaneity in their expression. Forty-one works—seven paintings and 34 sculptures—are on view in London. —Henry McGrath