This is a link to NFPA 79: Electrical Standards for Industrial Machinery
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=79&cookie%5Ftest=1
If you scroll down you will see a link that will let you view the book.
Chapter 13 will provdie information on wire identification (color).
Green or green with yellow stripe is Ground but there are exceptions (multi-conductor cable) that will allow solid green to be used as a non-grounded conductor. Personally I probably would not use green for anything but ground.
Orange is used for AC connductors that may be energized when cabinet (panel) power is OFF. Again, there are exceptions.
White with Orange stripe for AC grounded conductors that may be energized when cabinet (panel) power is OFF.
NOTE: In the past I was use to this being yellow but since yellow was used for 3 phase it got changed somewhere along the line.
AC grounded conductor (neutal) is white, gray, or 3 continuous white stripes on another color NOT Green, Blue, or Orange.
White with Blue stripe for DC grounded current carrying cunductors.
Black for ungrounded (HOT) AC or DC power conductors.
Red for ungrounded AC control conductors.
Blue for ungrounded DC control conductors.
There are exceptions.
That said I am use to seeing +24vdc use Brown and DC common use Blue, started seeing it over 25 years ago on European built equipment.