[Tutor] zip question

[R. Alan Monroe]

> I need some pointers to solve number 7. For what I can see on that picture
> the only hint is the gray line inside the .png drawing, but what can I do 
> with it?????????
> Just tell me where to start and I will try to get from there

Have you ever learnt about graphics and pixel colors? You know, like
red, green and blue combining to make colors and stuff?

Alan