Read the Amazon proposal carefully: They are looking for 500,000 square feet right now. And throw in the teaser of "up to 8 million in the future." 500K translates to, at most 5000 employees. Amazon employs 21K at their existing headquarters, not 50K. I doubt very much they would generate a State tax obligation remotely approaching $191 million per year. Or with 5000 employees $19 million per year. FICA goes to the Federal government, not Colorado. So Colorado won't be collecting a nickel of that money. Amazon will use or sell the tax credit generated which will offset the state income tax from the employees. Of course if most are paid like the warehouse employees at $12.50/hour there won't be any income tax collected. In fact they will be a net drain on the state. 

The real reason Amazon is looking for a new home - Seattle is thru subsidizing them. Lots of broken promises there. Look anything led to town by Jeff Bezos in the mouth very carefully.