Several of Frida's 1940 paintings are dominated by a yellow that only exacerbates the dour mood. This yellow is not sunny, it is glaring. The darkness in the interstices of a wall of leaves in a nocturne entitled Self-Portrait with Monkey, 1940, seems a more straightforward expression of Frida's gloom. Here a blood-red ribbon braided through her hair winds around her neck four times and around her pet monkey's once. The mood is claustrophobic.