Colour–luminosity diagrams of solar-metallicity L, T, and Y dwarfs. L0–T7 dwarfs are plotted as blue dots while T8–Y1 dwarfs are shown as orange dots. WISE1810 is plotted as a red dot. In the right panel, and for comparison purposes, two objects: WISEA J153429.75−104303.3, the first Y subdwarf candidate (known as “the Accident”; Kirkpatrick et al. 2021b), and WISE J085510.83−071442.5, the nearest brown dwarf to the Sun at 2.2 pc (Luhman 2014).