Suggestions

[iyenal]

I agree with you, an error in the PHP code can make inoperate the CMS.
By colors I mean : using colors with less black, with more of 65% luminosity, example for the Blue of the website (HXD) : 07C8FF
By interaction : Transparency (fading) animations, smooth transitions between pages, other font...
Example for board animation : http://codepen.io/codecalm/pen/wBgLYN
or for submit post : http://codepen.io/auginator/pen/oElzF or this: http://codepen.io/hakimel/pen/ZYRgwB
The interactivity make active the website so the users like navigating in the website,the popularity increase and the users visits increase also.
And for ergonomy, these (CSS3) transitions are integrated to the navigator,the speed navigation don't change so the users don't leave the website.

I suggest you to see some websites awards and new HTML and CSS features, they are awesome.