The shorter version of the tower is much better, but the overall footprint of the tower is still too massive. You've got the tower covering the entire site (200' x 265') going all the way up with maybe a slight taper. That's a 53,000 SF floorplate which is HUGE. Assuming a tower of that height is around 80 floors, that would be a 4.2 million SF building! Set the building's base to cover the whole site then at about 80 feet up have a substantial setback (south side only) to give you a 30,000 SF floorplate, then another setback around 1/3 of the way up to give you a 22,000 SF floorplate, then another setback around 2/3 the way up to give you a 15,000 SF floorplate. If you do that, you'll get it down to about 1.5 million SF, not counting the first 80 feet that covers the base, as most of that will be parking. I'd also suggest that at the first major setback at 80 feet you do all of it in from the south side, so that the non-setback part of the tower covers the corner at 18th & Broadway. Within each of the 1/3 and 2/3 tower sections, you can still do the slight taper/diagonal thing.
By comparison, Republic Plaza's tower has a 200' x 120' floorplate all the way up, which comes out to 24,000 SF. At 56 floors, RP comes in at around 1.3 million SF.
Finally, if you really want this to be more realistic, you'll have to move the location. That site at 18th and Broadway has a 400' height limit per the Downtown B-5 zoning. Anywhere in between 16th & 18th/Broadway, Larimer to Court, you'll have no height limit per se (only a Floor-area-ratio limit which I won't get into here as it's too technical) or between 14th and 15th. Here's a
zoning map for the B-5 downtown.
I like the overall design and I like the colors.