I'm finding it a little bit painful to look at, myself. I notice that you're using colour keywords for your CSS values. Unfortunately, the keyword colours are (mostly) too highly saturated. For instance, if you replace "blue" with the hex value "#0e53a7" for the body's background-color, you get something that is just as insistently blue, but without the eye strain that comes from scintillation.
A good place to go for colours is Color Scheme Designer 3. Their basic colour schemes may be bit limiting for a games-oriented site, but you can at least see how different colours work when they're placed side-by side, and it will allow you to pick colours that look "pure" without being oversaturated. You can still have the "pop" without making eyes pop.
If you're playing with HTML 5 anyway, you can probably safely assume CSS 3 (or parts of it, at least), so it might be worth playing around with border-radius and box-shadow. Note that you shouldn't have to use the vendor prefixes anymore for these -- all of the currently-available browsers either support the standard version, or have no support at all (border-radius is not supported on IE8). A little bit of rounding of the corners can make a HUGE difference to the look and feel of the site.
(Oh, and I realise that I've gone back and forth between "colour" and "color" here. "Colour" is the real word as I and millions of others spell it; "color" is a programming language keyword and a brand name.)
Another problem with using pure colours (red, green and blue, at least) is that it will cause a visual misalignment on the screen (for LCD-type and OLED screens, as well as Trinitron-type CRTs and plasma displays running at maximum resolution). Since only one of the three subpixels is lit up, and each pixel is composed of three vertical bars, one each of red, blue and green, pure colours will seem to shift slightly left or right compared to desaturated colours (which need to use some lit-up combination of all three subpixels).
Don't play with the white values until you see them against the final background colours. What seems glaring against a pure colour or black might just work perfectly well when set against a desaturated background. You won't know what contrast level is appropriate until you determine what the light text (or whatever) is being contrasted with. Mind you, all of this would be much, much easier if people ran properly-calibrated monitors. White should be paper-white (for relatively bright values of "paper", of course) rather than staring-into-the-sun-white. My main monitor (used primarily for high-end photo editing) is running at about 40% brightness (a little brighter during the day, a little dimmer of an evening); it's not even one of the brighter monitors on the market, and the default 100% brightness is out-of-control, eye-watering, blinding bright. I figure that people who run high-brightness monitors turned up full blast get what's coming to them (much like the headphone wearers you can hear from a city block away over a traffic background).