Is there a possibility to change it ?
Not as far as I know. I wondered whether it might be possible in IC614 where rulers are stored persistently, but there doesn't appear to be a width attribute.
You should contact customer support and request and enhancement.
In reply to Andrew Beckett:
so what can i change about the ruler ?
In reply to The Consultant:
In IC614 they can be stretched and moved - probably reshape too (I didn't try) because you can select vertices of the ruler.
Not sure what else you want to change?
i have "only" 613. was worth the try.
Actually, it appears that the ruler is the lpp "hilite drawing4" (at least in 5.1.41). So you can change the color and line style using the display resource editor.
In reply to dmay:
Works fine in 613 too.