feature request: increase the number of colors evolved in the color cycle

[HaoyangFan96]

I am make a plotting in which I want to assign each category a unique color. However, with number of categories increase, I found that the color actually repeats in a cycle

Right now I think Plotly by defaults only cycle through 10 unique colors, which makes sense according to the source

I am wondering if there is way to let user increase amount of colors evolved in the cycle or simply let user add their customized colors to the cycle?

Thanks

[etpinard]

I am wondering if there is way to let user increase amount of colors evolved in the cycle or simply let user add their customized colors to the cycle?

I think you're looking layout.colorway see example:

https://github.com/plotly/plotly.js/blob/master/test/image/mocks/layout-colorway.json

[HaoyangFan96]

@etpinard thanks for the help. Right now to me it seems like that the I need to first find a larger number of distinct and human-friendly colors and then supply to Plotly via colorway option. I wonder if there is way for me to get more possible colors from Plotly itself, so I won't have to import color values from third-party library etc

[alexcjohnson]

Interesting idea - I could imagine adding some named colorways... kind of like we do with colorscales where you can either specify [[fraction, color], [fraction, color], ...] or one of the predefined names. Would be a nice complement to plot templates.

@jackparmer this seems right up your alley 🎳

[HaoyangFan96]

@alexcjohnson I do some research on this subject and find some JS library like this which generates random distinct colors.
However, this are two problems with those libraries: although the generated colors are indeed distinct to each other, but there is no guarantee that they are distinct to each other in the maximum extent. In other words, it is possible for generate some "indeed" distinct colors which are hard for human-eyes to distinguish the difference. Also, a large portion of generated colors do not look nice to the user.

Can you take this two factors into the account while developing this new feature?

[gvwilson]

Hi - this issue has been sitting for a while, so as part of our effort to tidy up our public repositories I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our stack. Cheers - @gvwilson