Explanation for the Green, Orange and Blue Bars?

The green bar (niche value) is a function of search volume divided by competition difficulty. The main function is to eliminate keywords that have low search volume, but high competition, as these keywords aren't interesting.
However, a keyword can have a relatively low niche value and still be a good keyword. You should never look at just one single factor, when picking a keyword.

The "Rank 1-10" orange bar is an indication of how difficult it is to rank for a keyword. The more orange in the bar, the more difficult it will be to get your site listed in Google, for that keyword.
Here, less is always better.

The Adsense bar (blue bar) is a function of Cost-Per-Click multiplied by search volume. It's made specifically for finding keywords to target on an AdSense website, because the more traffic a keyword gets and the higher the cost for a click, the more money it can potentially make, on an AdSense site.