What is the difference in these hair colors?

I usually dye my hair a dark brown, and i seen where there is a color called ';ash'; brown. whats the difference in regular brown and ash brown?What is the difference in these hair colors?
Dark Brown: is more solid, and thicker looking.


http://www.hair4helmets.com/images/hair/Dark_Brown.jpg








Ash Brown: Is more light, and in my opinion, beautiful.


http://www.lovehairextensions.com/my_documents/my_pictures/C16_mediumashbrown6.JPGWhat is the difference in these hair colors?
';Ash'; colors are cooler tones, where a regular brown is warmer.





For example, Ash blonde is a cooler, almost more platinum-y blonde, as opposed to a honey blonde.
Ash is a cooler toned brown is tends to have a greenish cast sometimes. There are warm and neutral tones of brown also as well as 5 color levels.
Dark brown is warmer while ash is cooler toned. Ash is also lighter.