Thanks a lot to all of you for looking and commenting.I'm pleased that you like the bg as it is.
Ali : I agree with your remark about the colors in the piece : that's what attracted my eyes first when I saw the photo.All these greens and reds and yellow and blue) were so beautiful, I felt the urge to take my pencils.
Now, I did not use the same blues for the bg and the feelers (I used phtalo blue for the feelers and light ultramarine for the bg +other colors as well)but
it must be difficult to see on a monitor. And....he is not a "creepy crawly", he is a "marvellous god's creature"