[Bug]: 2 Colorblind Palettes are NOT colorblind friendly

[vincentott]

JASP Version

0.19.3

Commit ID

No response

JASP Module

Unrelated

What analysis are you seeing the problem on?

e.g. Raincloud Plots Module, Descriptives Module

What OS are you seeing the problem on?

macOS Silicon

Bug Description

JASP has three palettes that are supposed to be colorblind friendly:
"Colorblind", "Colorblind #2", "Colorblind #3".
However, the first two are not colorblind friendly, as demonstrated in the following:
(Thank you @davidmathlogic for the useful website!)

The first palette looks like this for three groups of a factorial design:

However, as seen here, this is not colorblind friendly:
https://davidmathlogic.com/colorblind/#%2378D0BA-%23DDBDAC-%23B2B2B2

The second palette has the same issue:

https://davidmathlogic.com/colorblind/#%2339C5A3-%23D2B38B-%23B3B3B3

Only the third palette seems good:

https://davidmathlogic.com/colorblind/#%23EDBAD4-%23C6E1AA-%237F7F7F

A test in the Descriptives module reveals the same problem:

https://davidmathlogic.com/colorblind/#%2300A174-%23BB7A57-%23666666

Expected Behaviour

Should we scrap the first two palettes, keep the third, and add more in the future?

Steps to Reproduce

1. Make a plot in JASP
2. Select the respective color palettes.

Log (if any)

No response

More Debug Information

No response

Final Checklist

• I have included a screenshot showcasing the issue, if possible.
• I have included a JASP file (zipped) or data file that causes the crash/bug, if applicable.
• I have accurately described the bug, and steps to reproduce it.

[vandenman]

There is indeed a bug in jaspGraphs in how the colorblind palettes get interpolated. That being said, there probably is no perfect solution here. For example, even if a palette is colorblind friendly, it may no longer be colorblind friendly when shown at a transparency.

After fixing the bug in jaspGraphs I obtain the following colorblind-friendly palettes:

For each color palette, the left panel shows the 8 built-in colors and the right panel shows what happens when the fixed version interpolates the 8 colors to 16 colors.

All palettes appear somewhat colorblind-friendly for the first few colors, but at ~4 categories they all seem to deteriorate.

Thoughts or suggestions?

[vincentott]

Is there a way to fix one or two palettes to 8 or 10 colors without any interpolation?
I.e., when there are 2 groups, the first 2 hexcodes are used, and if there are 5 groups, the first 2 + 3 hexcodes are used.
That could ensure a colorblind friendly consistency.

If more than 8 or 10 colors are needed,
then there could be an error/info to select a different color palette (e.g., the current Colorblind #3).

[tomtomme]

Also a transparency slider set to opaque by default would be handy.