Supposedly there is no center
There is no true center, or one that we will ever know. That's because shortly after the big bang space itself expanded faster than light. What we were left with was are own reference frame, the observable Universe, where all that we can observe is what hasn't expanded away from us faster than light, and hence gone forever.
Everything that is not gravitationally bound together is expanding away from everything else. For example, all the stars in our galaxy are bound together by gravity, all the galaxies in our galaxy cluster are bound together by gravity. However, the space between the galaxy clusters is expanding, everywhere. The farther away, and further back in time, the faster the expansion, until you get all the way back to the edge of the observable Universe, which gives the appearance that we are at the center of the Universe, as it would any other observer in any other reference frame, near or far.
There's even a "browning effect"
Once you negate all of the "peculiar motion", ie, our motion around the Sun, our motion in the galaxy, the galaxy's motion toward the center of the cluster, the wavelengths of light from all gravitationally unbound galaxies are stretched out and made longer because the space between them is expanding. This is called Red Shift; the longer the wavelength the redder the light, the greater the distance. It's similar to the Doppler Effect but it's not the Doppler Effect.
Another way to look at it is to imagine that all the expanding space is static (not expanding) and all the matter remains in place but is shrinking exponentially, the farther away the matter is the faster it is shrinking.
