I really like this for the Colts. A future pick likely in the #16-23 range, and you get an elite RB prospect on just the 2nd year of his rookie contract (a big part of why the Colts were willing to part with a 1st). I mean, yeah, in general you don't want to be trading 1st round picks for a RB in today's NFL - but in this specific situation I think they've done well.
Basically they moved up 14-18 spots to the top of the 1st round, while only losing 1 year + an offseason. And admittedly, with RBs that 1st year is valuable, but I think Richardson will be good enough that his shelf life will be considerably longer than most.
And of course the Browns are happy to tank, unhappy with Weeden.