The quote block has two styles, regular:
Gutenberg is more than an editor.The Gutenberg Team
Yes, it is a press, certainly, but a press from which shall flow in inexhaustible streams, the most abundant and most marvelous liquor that has ever flowed to relieve the thirst of men!
The quote blocks themselves have no alignments but the text can be aligned, bold, italic, and linked:
In addition to the quote block, we also have the pull quote, with a regular and a solid color style.
You can change the color of the border and the text with the regular style:
Or change the background color and text color with the solid color style: