i'm using xref for my a1 dwg..whenewer i change layer color and line type in xref it doesn't update it on my a1 sheet .. so I have to purge xref and bring it again  to my sheet .. any other changes work well. . does anyone know what's the problem? thanks .

It is better when you've already x-ref'ed a drawing into another and you have to go back and change colors. AutoCAd does not recognise that you have changed colors.  Sometimes you can shut down your autoCAD after changing the colors in your x-ref'ed drawing, but this does not work to well.  The best thing to do is to find your xref'ed layers and change the colors there. Makes for your original to stay set-up the way you had it.  I do not know what version of CAd your using, but in 2008 when you x-ref a drawing it asks if you would like to reconcile your x-refed layers this is the good time to change any colors you need before reconciling them to your complete layer list.  I hope this helps.

Thank you for your respond. I'm using Acad 2007, but I'm going to switch for 2008..which is probably improved. Thanks again..

If this is the problem, I think you simply detach the xref and reattach it. It must work. Only updating the xref is not sufficient lot of the times.
Regards.
Tom
www.indovance.com

Yes, that's what I'm doing all the time..there's no good coordination between sheets and xrefs.. hopefully cad 2008 will work better with this issue..thanks again..best regards .