The ND name colour is in a weird format on the website but it can be converted easily to something you can use elsewhere like on this server.
First go to http://www.binaryconvert.com/convert_signed_int.html and paste the colour code (eg, -255) into the 'Decimal' box. Then click "Convert to binary". Now in the second section you will see something like "0xFFFFFF01 = 11111111 11111111 11111111 00000001 ". You must take the first six digits after "0x", and before "01". Eg, in the example 0xFFFFFF01 = 11111111 11111111 11111111 00000001. This is your colour code which you can use with /namecolour (code) , or for general use online.
If you wish to know the red green blue values of this colour (ie. what you entered originally) you can go to http://www.javascripter.net/faq/hextorgb.htm and paste the code you just got. The example colour I used FFFFFF = 255 255 255 (full values for all primary colours = white!). You can use these with /namecolour too, with /namecolour r g b
Oh, Thanks m8