Just to help you and everyone else here, there is a new article on WordPress Site Reviews on the WordPress Codex, documenation site. This gives a good outline of what to expect from a review of your site here, and how to prepare to have your site reviewed. FYI.
Personally, I like the white overall look. I find no need for color to “attract” when the whole thing is clean and unusual “feeling”.
The sidebar must have been fixed cause it looks good now. You have obviously figured out how to change the words on the buttons for the search and sort features, but why not go a step further and change the look of the buttons to match the rest of the site. I’d go for a flat look using the blue-grey tons used as “shadows” along the sides of the site, with a complementary font to match the rest of the sidebar. Part of designing a look for your site is bringing ALL the elements into the site’s design.
To keep with the clean overall look, why not lose the validation links at the bottom of the sidebar. Since your site isn’t about validation, and you’ve done all the work, why bother? Go for clean.
Keep focused on the clean look and avoid the urge by many to clutter things up. It’s a great look.
On your single post page, I like that you have retained the sidebar to help with navigation and make the transition between the main front page and the post feel seamless. You do need to work on the fonts and style of the comment area, though. It doesn’t match the theme’s look at all.
All that stuff about the html you can use in the post – do you have people writing html in their comments to you? No, but if they do, they know the core stuff to use, so get rid of it. Clean, simple, uncluttered.
The categories on your single post page don’t work. I tried several different categories and they only reloaded the current page. They do work on your main page. Might want to check the validation and code on the single page.
The main page validates, though there are some errors in your CSS that may need attending to.
Overall, a clean and interesting look. Keep it that way. But keep the look of clean and interesting throughout your site so it is a whole blend not bits and pieces. Good work.