I only tested on a Live (downloaded ISO) MX-23.5 for Xfce x86_64.
1. There is an incorrect character in the code-window in the above link and for that reason the command fails. The reason is because the second dash used in "--create" is an "n" dash. It should be just a dash, not an "n" dash or not a "m" dash, just a standard dash. However the command is correctly shown in the blog post of the same subject https://mxlinux.org/blog/xfce-4-20-and- ... allpapers/.
2. After fixing the command, it successfully ran creating a "1" on the xfce-4 "single-workspace-number" value (the "single-workspace-number" entry was created after the command ran).
However, running the command would still not allow a solid color to be used for the desktop background. Changing the value to "0" would also not allow the Desktop to use a solid color. (FYI, disabling "Apply to all workspaces" on the Desktop > Background tab will change this value to "0".)
3. The only way I was able to get a solid color for the MX-23.5 Xfce (from an un-altered downloaded ISO file) was as follows:
- Desktop Settings > Background tab > "Style:" and select "None" > select a solid color from the first rectangle (closest to the "Solid color" drop-down).
At this point, regardless of the color chosen, the Desktop would only display a black background color.
- In the "Color:" drop-down, choose any of the three options (Horizontal gradient, Vertical gradient, or Transparent) > now go back and choose "Solid color".
- As soon as "Solid color" is chosen, the Desktop will display the color as chosen above.
