Actually you can edit your submission, upload a different file that meets the rules and be good. Also, there's no rule that says that you are allowed only one submission, you can have as many as you like. Many people participate more than once if they like the topic, and they can even win the same challenge more than once with different pieces. However, that does not mean that you should reupload your corrected image as a new submission, your other submission should be an entirely new piece. So if you make those corrections, you are good to go!

My mistake, I mis-read the contest rules. Thank you for pointing out the 11 colours though, I would not have realized the black background counts. I reposted it after correction in the forum thread, but I understand that there is only 1 submission allowed per contest and I flubbed this one. Will try again next week.

so what is the phrase you are depicting?

also, you have 11 colours, with background black being the extra colour