The phrase "a colour code" is correct and usable in written English.
It can be used when referring to a system that uses colors to convey information or categorize items.
Example: "The map uses a colour code to indicate different types of terrain, making it easier to navigate."
Alternatives: "a color scheme" or "a color classification".
Labelling on vending machines was a coloured dot on the slots, plus a colour code guide on the machine.
It's a piece of cake to operate: open it up, select your region and you're presented with a list of incidents/roadworks and a colour code saying (I presume, although there's no key) how serious an incident is.
A colour code, whereby a particular colour was assigned to a particular circuit connection, such as black leads for filaments, green for grid, was adopted throughout the world to facilitate manufacture and the tracing of faults.
The predicted path loss is superimposed on the floor plan using a colour code, explained in the figure caption.
In this mechanism, every node has a colour code based on how far it is from the sink.
Each node selects its parents with its colour code or with a colour code in order to be close to the sink.
Choose Well uses a colour coded 'thermometer' which aims to help people to link their symptoms with the most appropriate NHS service.
Iodine maps are encoded using a rainbow template with a colour coding from high to low iodine concentration, being from red (through yellow) to blue respectively.
The map's contour lines, however, are taken from a colour coded contour map developed by the U.S Geological survey in 2003.
It lists a synopsis of each altercation and where it took place, along with a colour coded legend that corresponds with the following categories: physical, verbal, hate propaganda, vandalism, threats, and online.
The similarity indices are then converted to electrostatic distances which are then displayed as a colour coded matrix called as the heat map (Fig. S2) and as a tree or a cluster dendogram (Fig. S1).
