Are all nail polish colours created equal?

I have declared war against nail polish that chips quickly.  I hate having less than perfect nails and do not have the time to do my nails every day.  So I have been looking for great nail polish.  The way I do this is to buy one bottle of a brand, use it and then decide whether I will ever buy that brand of nail polish again.

I bought a nude Essence and thought it was just horrible.  It does not even last a day.  I was so unimpressed that I threw the bottle away before I used all of it. 

And then I got a grey bottle of Sally Hanson and loved it.  After this, I read the following blog post about Nails Inc polish where the blue lasted much longer than the nude colour of the same brand.. 

 

My question is:  Does different colours from the same manufacturer last longer?  Is nude a colour that just does not last and I should not be painting all of Essence's polish in a bad light simply because the nude did not last.  And does it mean that Sally Hansen only impressed me because I tried a bluer colour?

Anyone out there who can solve this mystery?