The 230 and 250 SLs had the rubber mats in the foot wells.../... I don't know if they came in other colors../...
Yes, there were a wide variety of colours, and the interior was "colour tuned" to harmonise as a whole. The interior Code determines colours for carpets, sun visors, Hardtop inner ceiling, covers under dash, the piece in the middle wood tray, dash and window A pillar padding, window crank inserts etc.
For the rubber mat for driver and passenger six colours were specified: dark grey, medium grey, blue, sandy beige, brown or beige.