This is a pretty simple theme based on the JRPG Persona 3. The color scheme is intended to resemble the UI for the game's menus, and the checkerboard frame is intended to evoke (ha!) the unsettling, green-tinted atmosphere of Tartarus's halls.
The checkerboard texture is by ocd1c-stock on DeviantArt. (http://ocd1c-stock.deviantart.com/art/dingedcheckeredfloor-35651714)
The occasional splatter of blood on said tiles is from a brush pack by danieeel31, also on DeviantArt. (http://danieeel31.deviantart.com/art/10-Blood-Brushes-GIMP-129323322)