What is the right course of action?

You answered correctly. The yellow diamond traffic sign indicates that you are on the priority road. The additional sign below shows the course of the priority road, which curves to the left. Since you are following this main road and the other cars want to enter or cross this priority road, you have the right of way. Therefore, it is correct that you may drive through without yielding to either the blue car or the green car. In similar situations, always follow the direction of the priority road and give way only if you are leaving it or if specific signs indicate otherwise.