You probably just need to keep experimenting, but we can probably use the first example I posted as a starting point and example. Right click on the week heading cell, and select custom format cell. Set the background color to 220,220,220, which is the same gray as the grid lines. Do the same for the week data cell. You should then have the gray bar like I had, just with a heading and values in it. Easy enough to remove those, as indicated in the second example I posted, leaving you with only gray bars.
With the first document you posted, the gridlines are blue. After changing the before and after border colors, the verticle lines are gray, but the horizontal ones stay blue. Also, even after changing the first two columns to gray, there is still a bold black 'L' shape seperating the two columns.
Sounds like we're just not seeing the same thing, possibly because of different QlikView versions, or maybe there are user settings that override the document on either my machine or yours. Guess you'll just have to play with it. Sorry!