Note that the names of the themes at our home page are in two parts, e.g. Uptown - Black. The first section of the name - e.g. Uptown - is that of the base theme and the second section - e.g. Black - is the name of the variation of that base theme.
The Aarcade Admin > Install page of your Aarcade admin area only displays the Default variation of each theme. To find all available theme variations for a particular base theme, you must click the More button under that theme thumbnail in your Aarcade admin area.
For our example, to find and install Uptown - Black we would click the More button for the Uptown theme.
For more details on installing themes, refer to How do I install my Aarcade theme?