Click to change colour, shift+click to rotate, (option | alt)+click to change shape. Toggle borders. Save (opens in new tab).

Use URL parameters to change the grid size, i.e. ?dotWidth=64&gridWidth=12&gridHeight=12.

Use ?random=1 to fill the grid on load.

Colours are Kate Rose Morley's Rainbow Palette (CC0). Clearly inspired by LEGO Dots but I was reminded of this idea by the fantastic generative art on Monica Dinculescu's homepage.