Be less instrusive as requested (#57)

Add customization variables for tooltip colors

README.md

@@ -47,6 +47,7 @@ it to the popup help buffer provided by
 
 If you hit `M-x customize-group <RET> company-quickhelp <RET>` you'll
 find a few variables you can diddle.
+For instance, you can change the help popup text background and foreground colors.
 
 You might also want to put this in your `init.el`:
 

company-quickhelp.el

@@ -64,6 +64,18 @@ be triggered manually using `company-quickhelp-show'."
                  (const :tag "Don't limit the number of lines shown" nil))
   :group 'company-quickhelp)
 
+(defcustom company-quickhelp-color-foreground nil
+  "Popup text foreground color."
+  :type '(choice (color)
+                 (const :tag "Default" nil))
+  :group 'company-quickhelp)
+
+(defcustom company-quickhelp-color-background nil
+  "Popup text background color."
+  :type '(choice (color)
+                 (const :tag "Default" nil))
+  :group 'company-quickhelp)
+
 (defvar company-quickhelp--timer nil
   "Quickhelp idle timer.")
 
@@ -159,7 +171,9 @@ currently active `company' completion candidate."
             (let* ((frame (window-frame (selected-window)))
                    (max-width (pos-tip-x-display-width frame))
                    (max-height (pos-tip-x-display-height frame))
-                   (w-h (pos-tip-string-width-height doc)))
+                   (w-h (pos-tip-string-width-height doc))
+                   (fg-bg `(,company-quickhelp-color-foreground
+                            . ,company-quickhelp-color-background)))
               (cond
                ((> (car w-h) width)
                 (setq doc (pos-tip-fill-string doc width nil 'none nil max-height)
@@ -168,11 +182,11 @@ currently active `company' completion candidate."
                     (> (cdr w-h) max-height))
                 (setq doc (pos-tip-truncate-string doc max-width max-height)
                       w-h (pos-tip-string-width-height doc))))
-              (pos-tip-show-no-propertize doc nil (overlay-start ovl) nil timeout
+              (pos-tip-show-no-propertize doc fg-bg (overlay-start ovl) nil timeout
                                           (pos-tip-tooltip-width (car w-h) (frame-char-width frame))
                                           (pos-tip-tooltip-height (cdr w-h) (frame-char-height frame) frame)
                                           nil (+ overlay-width overlay-position) 1))
-          (pos-tip-show doc nil (overlay-start ovl) nil timeout width nil
+          (pos-tip-show doc fg-bg (overlay-start ovl) nil timeout width nil
                         (+ overlay-width overlay-position) 1))))))
 
 (defun company-quickhelp--set-timer ()