How do I set cursor colours per evil-state in the (non-GUI) text terminal?

Question

In the terminal, (set-cursor-color "red") has no effect, so the only way I can distinguish insert from normal mode under evil-mode is through the <N> or <I> on the modeline. Is there a way to set the cursor colour even in text terminals? (I use sakura with TERM=xterm-256color if that matters.)

Answer 1

Here's a hack that seems to work:

(defun evil-set-cursor-including-terminal (orig-fn specs)
  (if (display-graphic-p)
      (funcall orig-fn specs)
    (when (= (display-color-cells) 256) ; otherwise messes up tmux under xfce4-terminal
      (pcase specs
        ((and (or `(,colour) `(,colour . ,shape))
              (guard (stringp colour)))
         (send-string-to-terminal (concat "\033]12;" colour "\007")))))))
(advice-add #'evil-set-cursor :around #'evil-set-cursor-including-terminal)

The exception is replace-state, which doesn't seem to change back to the normal colour (so I have to insert/visual and exit to get back normal colour).