I tend to think an offworld colony would prefer their own altcoin or native barter system. In the event of a solar flare from the sun or communications blackout all financial transactions and economic activity for a colony would grind to a halt. In designing an offworld economic system various redundancies could be built in to address the event of catastrophic communications failure, which could negate the possibility of an earth dependent system being utilized.
My next article will attempt to address the pros and cons of each world having its own currency. I hadn't thought of the solar flare disruption angle yet, though my immediate thought is that established Lightning channels would continue to work locally until the comms cleared up. Sabotage or total failure of the comm system is also a possibility, but hopefully the demand for communication will have created multiple redundant channels ahead of this event.
An offworld currency system may need to be flexible to adapt to unforeseen or shifting economic & financial conditions which could rule out bitcoin with its rigid algorithmically determined supply.
I would argue the opposite: meddling with the money supply often causes more problems than the original crisis. As long as it's divisible, any quantity of money is enough for an economy. Long article
here if you're curious.