A lot of Blenderheads want to customize Blender to their designing preferences. Some like dark colors and others like light colors. Some like blue others, such as VenomGFX like pink! Back in the day, people would pass their default blend files around. When this became cumbersome, Willian P. Germano created the simple Blender Theme Script which allowed for a whole new way of saving and loading Blender Themes. It has now become one of the many features that Blender offers (File>Export>Save Current Theme...).
Blender Themes have been passed around the internet since then and have somehow arrived in the unofficial Blender Theme Repository. Among these are the themes of popular Blender artists such as @ndy and Basse. Be sure to send the Blender Theme Repository your custom Blender Theme for inclusion is this one stop source for cool Blender Themes!