This is typical with dark or intense colors. You will need to repaint but this time do the following;
* Cut-in and roll one wall at a time to keep a wet edge.
* Roll as close to the ceiling and corners as possible. Try rolling horizontally at the ceiling. If you can get within an inch, this would be good, less chance you will notice any color differences.
* Add Flotrol to the paint, both cut-in and rolling, to slow down its dry time. This will help the paint blend.
* Use your true finish paint. No need to buy a flat paint or do any priming.