Would it pass the trouser test?

I've been doing the 'sew your own wardrobe' for a number of years now, and the one thing that has continued to trip me up is the whole idea of a neutral. 

Almost every wardrobe plan has a variation of: Sew a neutral base and add colour to it.  Inside column, outside column, capsule, all of them use neutrals as the base.

But--what is a neutral? And would I really wear it?

Some people would say that it is a colour found in your eyes, hair or skin tones.  There are a lot of great references for this idea, not the least of which is 'Triumph of Individual Style' (love this book; if you don't own it, you should get a copy!) and Nancy Rix's blog and wardrobe ideas.  Even so, I have hesitated to really use the idea until today, reading on Artisan's square, when I came across this comment: would you sew trousers in it?

There are lots of colours I love.  Seriously love.  Like red and white and electric blue.  White is the one that really stands out to me--it is a neutral.  Lots and lots of people wear trousers in white.  Not me though.  For my wardrobe, if it won't pass the trouser test, it isn't a neutral.  Neutrals are deep and dark in my world--dark denim, grey, black and if I really work at it--deep plum, and navy.  But I have to work at the last two.  

So, what colours, dear reader, are your neutrals?  And, would you wear trouser in them??