I agree. Coloring your whole post is like dressing like Bjork. It's just for attention. It took computer designers 20 years to figure out that despite all the neato colors easily available on a computer screen, there's a reason why every business and school project is written/typed/printed on off-white paper with black text. It is, hands-down, the easiest to read across the board.
As far as drawing attention via colors, that generalized statement is not a graphic design principle. The graphic design principle is the bolded "not" in the previous sentence. You accentuate specific details amongst a larger text set to draw attention to those pieces. If you color the whole thing you're defeating the purpose.
If you want proof hop over to dribbble.com. It's a site where professional graphic designers post their work for critique and recognition. The site itself uses a neutral background with neutral contrasted text, reserving color for the thumbnails of contributor projects. Also, if you browse the contributions, you'll notice the vast majority of site designs use neutral backgrounds and neutral text when they want you to read and comprehend an informational paragraph. Color is used for a reason to draw attention to pictures, links, headers, advertisements and other specific pieces that just need to grab you for a second away from the text.