Is there such an indicator as this?

for metatrader, is there an idicator that would only show the outer bollinger bands and not show the center line ?

oops nevermind, I just figured it out. Overlay a simple moving average and make it’s color black

It would be interesting to know why you don’t want to see the middle bollinger band (BB).

As you correctly pointed out middle BB is simply a 20 period SMA. However, the upper and lower BB are 2 standard deviations from SMA and they are measured with respect to the middle BB. At the very least the middle BB is a natural trend line.