Add configuration for GNOME

.bash_completion

@@ -11,6 +11,40 @@ complete -W '--force' dotfiles-install dotfiles-update
 complete -W '--quieter' generate-shell-completions
 
 
+_color_palette() {
+    local cur="$2" prev="$3"
+    local flags='--scheme --show --write'
+
+    # Values for `--scheme`, in both the "--scheme value"
+    # and the "--scheme=value" form
+    case "$prev" in
+        --scheme)
+            mapfile -t COMPREPLY < <(compgen -W 'dark light' -- "$cur")
+            return
+            ;;
+        =)
+            if [ "${COMP_WORDS[COMP_CWORD - 2]}" = "--scheme" ]; then
+                mapfile -t COMPREPLY < <(compgen -W 'dark light' -- "$cur")
+                return
+            fi
+            ;;
+    esac
+
+    # Offer only flags not already on the line
+    local flag remaining=''
+    for flag in $flags; do
+        case " ${COMP_WORDS[*]} " in
+            *" $flag "*) ;;
+            *) remaining="$remaining $flag" ;;
+        esac
+    done
+
+    mapfile -t COMPREPLY < <(compgen -W "$remaining" -- "$cur")
+}
+
+complete -F _color_palette color-palette
+
+
 # Fuzzy completion with the `**` trigger
 # (e.g., `vi **<Tab>`, `ssh **<Tab>`)
 #