I use the dark GNOME theme in gnome-terminal.

Capture d’écran du 2023年12月31日 20-12-11

Lines 1 and 2 use the default theme, so hostcolor is used:

As you can see on the screenshot, the name of the machine is "serveur", and it causes the issue.

The colour of the prompt is the same as the result of this command:

echo "serveur" | md5sum | cut -f1 -d' ' | tr -d '\n' | tail -c6
1d410f

Lines 3 and 4 use a patch

I forced the colour on this environment:

diff --git a/functions/fish_prompt.fish b/functions/fish_prompt.fish
index 68b8125..7de249f 100644
--- a/functions/fish_prompt.fish
+++ b/functions/fish_prompt.fish
@@ -16,7 +16,7 @@ function fish_prompt
 end
 
 # Setup colors
- set -l hostcolor (set_color (uname -n | md5sum | cut -f1 -d' ' | tr -d '\n' | tail -c6))
+ set -l hostcolor (set_color 803080)

Proposals

I don't have any idea to solve this, hostcolor may only use a color than is not too light or dark. Or a background may be used so that the prompt always have some contrast.