For the fly screen:
Many people succumb to the mistaken belief that a bright (white) flyscreen acts less conspicuous than a dark (black / anthracite). However, this is not the case. A bright flyscreen immediately catches the eye, even at great distance, which is not the case with a dark. This is because white flyscreen light break / reflect differently and so a milky shine. A dark lattice absorbs the light here easily. Here it should be mentioned that the disadvantage in the dark grating is that the space is a little darker. But that is (at least to my mind) with the naked eye is not visible!
I recommend a white grid as discreet privacy! As mentioned the white grid falls on more. The view in the room (as well as out of the room) is so difficult. Also note that a white lattice incredibly quickly dirty! Here may need to be replaced more often.
You make a mistake when choosing colors and wanted but rather a dark? No Problem! Just half a year left hanging, the problem then moves away by itself;)
For fixing is said Tesa is indeed incredibly expensive, but holds it! I have had many cheap grid in use are almost all fallen off after a short time (adhesive Velcro)! Since I use Tesa, the grid for years now holds (on wood!). Absolute recommendation. Rather spend a few more euros, but longer saved what.
At uploaded by me pictures you can see that as the dark grid is hardly noticeable.