Change colour in header cell

http://www.wackynation.com/rps-challenge

I am looking to create four boxes that sit side by side in a row. As you see on the webpage above I have achieved this, but there are 3 issues that I cannot figure out;

1) How do I change the red colour in the header cells so that each one is a different colour e.g. red, green, yellow and blue?
2) As you see for some reason the first box sits higher up than the others on the page
3) Is it possible to remove some of the blank space between the header text and the cell bottom line?

The code that I am using is http://snippi.com/s/ypt8cag

Thanks