Curves imported in to rhino from autocad - problem with changing the color

Im working on a document with imported curves from autocad into rhino - i need to change the color of the curves - they are black and i need them to be in blue - however the color change is not showing up.
Is there anything that i can change with the curve definition - to enable the lines to show up in a different colorimported lines not changing colour.3dm (1.4 MB)

Well, some of the curves in your file have color set by layer and others (the black and gray ones) have color set by object. You can select all the black/gray ones and either change their object color to blue, or you can change it to by layer and put them on a blue layer…

HTH, – Mitch