Revert "[spacemacs-bootstrap] Fix mode-line evil state foreground"

This reverts commit 4562da2.

Revert reason:
emacsclient broken on develop branch by commit 4562da2
syl20bnr#13766

CHANGELOG.develop

@@ -1323,7 +1323,6 @@ Other:
   - Fixed ~SPC h f~ =helm-spacemacs-help-faq= (thanks to duianto)
   - Fixed =cl= package deprecated =letf= (thanks to duianto)
   - Fixed origami bindings in normal mode (thanks to Tomasz Kowal)
-  - Fixed mode-line evil state foreground color (thanks to duianto)
 *** Layer changes and fixes
 **** Agda
 - Fixes

layers/+distributions/spacemacs-bootstrap/funcs.el

@@ -58,46 +58,17 @@ For evil states that also need an entry to `spacemacs-evil-cursors' use
   ;; visibly flashing in treemacs buffers
   (eval `(defface ,(intern (format "spacemacs-%s-face" state))
            `((t (:background ,color
-                             :foreground ,(spacemacs/get-darker-color-of-face-fg-or-bg
-                                           'mode-line)
+                             :foreground ,(face-background 'mode-line)
                              :inherit 'mode-line)))
            (format "%s state face." state)
            :group 'spacemacs)))
 
 (defun spacemacs/set-state-faces ()
   (cl-loop for (state color cursor) in spacemacs-evil-cursors
            do
-           (set-face-attribute
-            (intern (format "spacemacs-%s-face" state))
-            nil
-            :foreground (spacemacs/get-darker-color-of-face-fg-or-bg 'mode-line))))
-
-(defun spacemacs/get-darker-color-of-face-fg-or-bg (face)
-  "Return the darker color of the FACE foreground or background,
-based on the luminance of the FACE background.
-
-If the FACE background is brighter than 0.5,
-return the FACE background,
-otherwise return the FACE foreground."
-  (if (> 0.5 (rainbow-x-color-luminance (face-background face)))
-      (face-background face)
-    (face-foreground face)))
-
-;; source: http://elpa.gnu.org/packages/rainbow-mode-1.0.4.el
-(defun rainbow-color-luminance (red green blue)
-  "Calculate the relative luminance of color composed of RED, GREEN and BLUE.
-Return a value between 0 and 1."
-  (/ (+ (* .2126 red) (* .7152 green) (* .0722 blue)) 255))
-
-;; source: http://elpa.gnu.org/packages/rainbow-mode-1.0.4.el
-(defun rainbow-x-color-luminance (color)
-  "Calculate the relative luminance of a color string (e.g. \"#ffaa00\", \"blue\").
-Return a value between 0 and 1."
-  (let* ((values (x-color-values color))
-         (r (/ (car values) 256.0))
-         (g (/ (cadr values) 256.0))
-         (b (/ (caddr values) 256.0)))
-    (rainbow-color-luminance r g b)))
+           (set-face-attribute (intern (format "spacemacs-%s-face" state))
+                               nil
+                               :foreground (face-background 'mode-line))))
 
 (defun evil-insert-state-cursor-hide ()
   (setq evil-insert-state-cursor '((hbar . 0))))