There was a time not too long ago where you could get custom colors or at least have selection of multiple colorways on non-halo bikes. This disappeared mostly due to excess cost and low ROI for the companies. Most smaller to mid-level companies nowadays generally will offer two color schemes per frame; a wild and mild per say. The big boi’s like Trek and Specialized have custom color programs on certain models, but they are spendy and you will not find them available on anything beyond their top-shelf offerings. However, if you are an industrious type you can custom paint any frame (including carbon) yourself for really inexpensively via using Spray Bike.
I have painted a couple of frames with it and it works exceptional well. It is tougher than frames I have had powder-coated and the biggest cost is just the time you put into it.