rocky-vm-setup: tmux COLORTERM pass-through for helix truecolor

2 files changed, 14 insertions, 1 deletions

diff --git a/prompts/skills/rocky-vm-setup/SKILL.md b/prompts/skills/rocky-vm-setup/SKILL.md
index cf287e8..f21061a 100644
--- a/prompts/skills/rocky-vm-setup/SKILL.md
+++ b/prompts/skills/rocky-vm-setup/SKILL.md
@@ -114,6 +114,9 @@ set -g window-status-current-format ' #I*#[bg=brightred,fg=white] #W '
 # TERM inside tmux — must advertise 256 colors so helix/fzf/etc work
 set -g default-terminal 'tmux-256color'
 set -ga terminal-overrides ',xterm-256color:Tc,*-256color:Tc'
+
+# Pass COLORTERM through from outer SSH session so helix knows truecolor is available
+set -g update-environment 'DISPLAY SSH_ASKPASS SSH_AGENT_LAUNCHER SSH_AUTH_SOCK SSH_CONNECTION SSH_TTY WINDOWID XAUTHORITY TERM COLORTERM'
 ```
 
 This is deployed by the `home_tmux_rocky` Rex task (runs only when `hostname =~ /rocky/`).
diff --git a/prompts/skills/rocky-vm-setup/references/tmux.md b/prompts/skills/rocky-vm-setup/references/tmux.md
index 42ce58e..c861d78 100644
--- a/prompts/skills/rocky-vm-setup/references/tmux.md
+++ b/prompts/skills/rocky-vm-setup/references/tmux.md
@@ -59,4 +59,14 @@ set -g default-terminal 'tmux-256color'
 set -ga terminal-overrides ',xterm-256color:Tc,*-256color:Tc'
 ```
 
-Without this, tmux defaults to `TERM=screen` (8 colors) and helix themes break.
+Without `default-terminal`, tmux defaults to `TERM=screen` (8 colors).
+
+### Truecolor (24-bit / 16777216 colors)
+
+For truecolor themes in helix, `COLORTERM=truecolor` must also be present inside tmux. tmux strips it by default via `update-environment`. Pass it through:
+
+```sh
+set -g update-environment '... TERM COLORTERM'
+```
+
+Without this, helix sees `COLORTERM=` and falls back to 256 colors only, breaking truecolor themes.