flycheck-color-mode-line does not colorize properly the powerline

[arranger1044]

I am not able to have flycheck-color-mode-line coexist properly with powerline since it does not colorize the endings of the separators as show in this picture:

Here is my configuration:

;; powerline
(require 'powerline)
(powerline-center-theme)
;; flycheck-color-mode-line
(require 'flycheck-color-mode-line)
(eval-after-load "flycheck"
    '(add-hook 'flycheck-mode-hook 'flycheck-color-mode-line-mode))

but I suspect I'm missing something