Almost certainly a bad DLP chip. Start looking for a new projector. You could call Optoma to ask what it might cost but they will likely require you to send it in for an estimate. Ask about some accommodation on the cost to fix it...not likely but one should always ask on a product that does not reach a normal life expectancy.
In some cases you can buy the DLP chip on the open market and replace it yourself. I frequently see them between $100-200, so I'd say $150 in parts. Note, you must replace the DLP chip with the same or compatible part ##.