Is there a standard color list to keep adding new colors to a plot while retaining old colors?

Question

My users pick one or more data sets to graph on a single canvas. The sets are color coded to distinguish between sets (all screenshots are for demonstrative purposes from demo utility):

• BLUE=temperature inside
• RED=temperature outside

More and more data sets are becoming available as the project develops, so the user picks from a larger and larger list of measurements:

• BLUE=temperature inside
• RED=temperature outside
• GREEN=other temperature inside
• PURPLE=pressure outside
• ORANGE=beam energy fluctuation
• BLACK=neutron count

The more instruments we have the more colors we need, so we necessarily start filling out the hex color wheel:

• BLUE=temperature inside
• RED=temperature outside
• GREEN=other temperature inside
• PURPLE=pressure outside
• ORANGE=beam energy fluctuation
• BLACK=neutron count
• LIGHT BLUE=photon count
• DARK PURPLE=water flow rate
• GRAY=RF intensity
• ...

I understand with dozens of data sets (and growing), there is no way a user can see every set simultaneously with sharply contrasting colors. However, what I would like is a list of (many) predetermined colors, spaced as sparsely on the color wheel as possible, to assign to data sets as we keep adding instruments. This way, the first data sets have the same colors they originally had even though we keep adding new ones (backwards recognizability), and the new ones are as different as possible from the existing list.

My question is: do designers have a standard color list I can use to associate with new instruments to maximize contrast between any two series?

Answer 1

color brewer is designed for maps but it will give you colours that are optimised to be as differentiable as possible.

It has a maximum of 12 colour classes

Answer 2

There are a few pre-made category color sets for Datavis, made by Mike Bostock, that go up to 20 colors:

However, in my POV they are not very interesting aesthetically, so if you are into a custom or advanced color work, you could try the ColorBrewer by Cynthia Brewer, as @icc97 said.

Answer 3

There is no standard list, but there are rules how colors come together or contrast. I use Paletton when I have any questions or doubts about colors. There are plenty of options there to research and experiment. I think it might be a good starting point for your list.

Answer 4

No, and in fact most of the default colour palettes of standard applications are not particularly suitable because it is difficult to take into account the number of datasets you are going to plot or display.

However, there are a couple of strategies you can consider when you are going to be working with a very large dataset (with many data series):

1. Provide grouping options based on logical sequences (e.g. date, time, type of measuring device) that allows you to use similar colours that relate to similar values or data seriesso you don't have to juggle too many colour types.
2. Use not only colours, but different line or stroke patterns (e.g. dashes, dots) that will give users other ways to distinguish between data series
3. Reduce the amount of information that you show on the screen at any given time, by giving the user options to filter and sort the data series.