Can a buyer will be force to keep a car whose registration does not match the color?

I bought a car from a dealership. The salesperson and I agree to left the card in the dealer for two days. In my home I found out that the contract paper has the wrong color of the vehicle, but no the registration. I talk to the sales person and because he did not see this important I told him that I do not want the car, anyway he has the car in the dealer. Five days later I have the car in my6 parking. I called and I asked why , because I was ckear that I do not want the car. The sales person told me to call the manager . After calling back to from (manager and salesperson) their answer was that the car was mine. I went back to the agency and returned the car. The manager told me that he acept the car but it is mine. I left the car in the agency. Please advise me