I mixed the color I wanted (obviously from a pallette they had) at a shop on Umm Suqueim Road, on the Barsha side (its on the same side as Marina Furniture, opposite the petrol station that has Lulu supermarket behind it). They had a big variety of colors and there was one that they didn't have but I had gotten from another shop that sells Jotun, and they still mixed it for me. Its all computerized. Check out the colors they have online and maybe you can take the reference of the color you want from there? Also, Jotun there was cheaper than Jotun in Ace.
Am hoping to do the same once I settle on DD's room! But just one wall in hot pink and the rest in very light pink:)
Good luck! and let me know where you find some!