Youre on the right track and bring up a valid point. This same theory applies to rifle cases and bags which you might carry a gun in during an emergency. Often referred to as a Sneaky Bag in some circles.
Maxpedition makes excellent quality products for example, but I might agree a Faclon II covered in MOLLE in OD green might draw more attention to you than a black Jansport backback that you dumped your kids school books out of. It doesnt apply to just bags though. If youre wearing the entire 5.11 catalog and jungle boots and have an RC-6 on a drop leg rig you will draw attention to yourself more than an average Joe.
Ive accepted that I will make decisions on gear based on what will best suit my needs. And these are things I try to keep in mind. If things got really bad for XYZ reason and my AR and a chest rig worn over a vest were what I wanted to be wearing would I draw more attention to myself than that vest worn under a jacket and my carry gun concealed?
Blend in, dont draw attention, get to where you need to be, then adjust your gear accordingly. YMMV.