> From: sbbrouwer@gmail.com
> Date: Thu, 13 Sep 2012 13:45:20 +0200
> Subject: Re: [NTG-context] Change color of EPS file.
> To: ntg-context@ntg.nl
> CC: ryzz@hotmail.fr
> 
> Hello Pol stra,
> 
> Off-topic for this mailing list, but on-topic for you: You can do this
> with Inkscape.
> 
> * Install Inkscape: http://inkscape.org/download/?lang=en
> * Open the EPS in Inkscape
> 
> Working white-on-white sucks, so
> * File > Document properties > click to the right of 'Background:',
> below the Default units dropdown
> * Choose something nice and pastel-coloured with alpha (opacity) set
> to non-zero.
> 
> * Select the object
> * Object > Ungroup (Ctrl+Shift+G) to make Inkscape see the individual
> paths, instead of a single EPS object
> The single rectangle selecting the object has now turned into a heap
> of rectangles.
> * With the colours at the bottom, set the fill to be red with click
> and/or set the stroke to be red with Shift+click
> 
> This will probably not have the desired effect because some of the
> constituent paths will have black fill+transparent stroke, and with
> others it will be the other way round. So you'll have to set
> fill/stroke individually.
> 
> * Select paths in turn, and set their fill/stroke as appropriate.
> Their respective values are shown in the bottom left. If you select
> multiple paths and their fill/stroke is different, it will be shown as
> "mixed"; when multiple paths' fills/strokes are not mixed they are
> identical, and you can change them all at once.
> 
> (Depending on ... file-related things ... you may need to use Path >
> Object to Path at some point, and possibly Path > Break Apart. But
> probably not.)
> 
> Good luck!
> 
> --Sietse

Thanks Sietse

I already tried the inskape way, but it’s too much work if you have many files to proced.
But your answer gave me the idea to use imegemagick, so I found this trick:
convert -background none -density 300 -negate a1.EPS bbb.png
I do not know why, but the same command with an EPS output gives me a white background so I had use a png file.
The result is good enough for me.
Thanks again