As days get shorter some leaves take that as a signal and stop making chlorophyl. That chlorophyll is what gives the leaves their green color, and what is left in those leaves will break down. The green fades and disappears. Yellow, orange, and red colors left in the leaves and now uncovered, become visible.
This is a leaf of Virginia Creeper (Parthenocissus quinquefolia) with its five leaflets, which seem to be showing their independence, doing their own thing, and creating a fun look of red and green.
Even now, autumn is creeping up on us.