Change filling color of rendered image

Is it possible to change the color of the image being rendered? I have a black background and therefore I can't see the equation rendered! Then my solution would be to show it as white.. is this possible?

Hi,

In the full toolbar you can select a 'black' background then you see white text on black.

Alternatively add \bg_black to the start of the HTML request, i.e.

<img src="http://latex.codecogs.com/gif.latex?\bg_black 1+2*3" />