I suggest reversing the filler with hyaluronidase, this is likely due to filler placed superficially. I do not think this is pigment and if it was it could be removed with co2 or q switched/pico lasers. In the future cannula injections prevent complications. Best, Dr. Emer.
Sorry to hear your issue. Unfortunately, you most likely had a little bleeding that pigmented your skin which will resolve but could take several weeks to months. Use a concealer in the meantime.
It is difficult to tell from the photo, but there are two possible reasons something like that could happen. number one is due to some blood cells getting stuck in the skin and that can resolve over time on its own, or can be treated with a laser. the second reason is due to the product being injected too superficially and something called the tyndall effect happens. this can only be corrected with injection of hyaluronidase.
The discoloration may be some red blood cells trapped in your skin which may go away in due time. However, the bluish coloration most likely is the Tyndall effect that we see when a hyaluronic acid filler is placed too superficially. If that is the case then that may be reversed by injection of hyaluronidase. Please see an experienced, board certified injector for further evaluation.