I have to agree with bowlingshirt - no producer is going to post negative reviews of their product on their website.
And, like Jcas mentioned, I too have always heard that the darker the color the more flavorful. True, as McNerd mentioned, some do come in cans or dark colored glass where you can not see the color ... but many come in clear glass where you can see the color.
While "reviews" can give you some ideas about what other people think - the final decision is how does it taste to you? And, while everyone is looking at the big brands - sometimes a dark horse slips in.
About 4-5 years ago I was passing by a Cost Plus World Market that had just opened up about a year earlier and they were having a 50%-Off After-Christmas sale. Ok - I had to stop in and browse ... and picked up a liter bottle of their store brand EVOO for $2.50. That night I made some Baba Ganoush and used it ... the next day I went back and bought 8 more bottles. Been using it ever since. It was better than anything I had found on the supermarket shelves. It's not the best I ever had ... that distinction goes to a small (100 ml) bottle a patient's husband gave me that he had brought back from a small Greek island on a buying trip.
It's like wine - try a bottle and see if you like it.