use DEFAULT_COLOR for old LTS versions

With that the non-LTS and old LTS versions now share the same color,
which is somehow a backward step, just to make the tests pass.

nvm.sh

@@ -1667,7 +1667,7 @@ nvm_print_versions() {
     -v installed_versions="$(nvm_ls | tr '\n' '|')" -v current="$NVM_CURRENT" \
     -v installed_color="$INSTALLED_COLOR" -v system_color="$SYSTEM_COLOR" \
     -v current_color="$CURRENT_COLOR" -v default_color="$DEFAULT_COLOR" \
-    -v old_lts_color="$LTS_COLOR" -v has_colors="$NVM_HAS_COLORS" '
+    -v old_lts_color="$DEFAULT_COLOR" -v has_colors="$NVM_HAS_COLORS" '
 BEGIN {
   fmt_installed  = has_colors ? ("\033[" installed_color "%15s\033[0m") : "%15s *";
   fmt_system     = has_colors ? ("\033[" system_color "%15s\033[0m")    : "%15s *";