My prediction is much less wacky than predicting a colony by 2050.

I think everyone overestimates the public interest and "excitement" over going to Mars. The reason we haven't been back to the Moon in 50 years is that the public lost interest after the ~third or fourth launch, and stopped tuning in to the broadcasts. With ever-improving VR technology, I'd predict that more and more people would be satisfied enough with a VR experience of Mars, and be done with it. The need to physically "go" to a place and claim it for yourself will be a thing of the past.