'(flymake-errline ((((class color)) (:underline "OrangeRed"))))
'(flymake-warnline ((((class color)) (:underline "yellow"))))

;; flymake
(defun my-flymake-show-next-error()
  (interactive)
  (flymake-goto-next-error)
  (flymake-display-err-menu-for-current-line)
  )

;;
;; Setting some C / C++ defaults
;;
(add-hook 'c-mode-common-hook
          (function (lambda ()
                      ;; more stuff here
                      (flymake-mode t)
                      (global-set-key  "\C-c \C-v" 'my-flymake-show-next-error)
                      )))