Is Mars really a better place to colonize that Luna? In terms of raw materials, I think they are about the same, except for sunlight. Mars has a lot less than Luna or Earth orbit. The gravity is 38% of Earth's (compared to 16% on the moon). Both probably require regular exercise in a centrifuge to maintain human health. Mars' atmosphere is very little CO2, so any artificial atmosphere creation would probably be from the rocks instead of from Mar's existing atmosphere. Besides, that just gets you the Oxygen. Even if they refined it by splitting the CO2, we would still need a lot of Nitrogen or some inert gas like Argon for habitats and excursion compressed air.
Shipping time from Earth would be much much worse for Mars. I think the combination of Earth orbit and Luna makes more sense.
Mars colonies will make a lot more sense in a 1000 years or so, when we can terraform it from space. Grab some liquid gases from Jovian planets to give it a usable atmosphere. Then plant some useful biota there to make it compatible with human life. Then we can have vacation stays on Mars as pseudo-birds, flying around under our own power. Of course, we could do that on the moon a LOT sooner, inside big domes.