Here's some technical details about the colors:
Body background-color: #FFFFFF, rgb: 255, 255, 255
Code/Blockquote background-color: #F5FDFF, rgb: 245, 253, 255
It's nearly white! Color-wise, I would classify it under gray not blue. I suggest increasing the saturation by about 8 units to #E0F9FF, rgb: 224, 249, 255.
For comparison, the background color here on Meta.SU is #EEEEEE, rgb: 238, 238, 238.