Why aren't skyscrs more vibrant colors?

That most architects want their buildings to dominate the horizon is an understatement. Today tall skyscrs are being built in record levels. Meanwhile, most of them are dull colors like black, gray, blue, and brown. Though I'm not a big fan of Dallas, one thing I admire is the night skyline. All the buildings there have colorful lights. Why don't they paint skyscrs red, blue, green, yellow, purple, orange, and teal? How about vermilion, amber, lime, cyan, coral, and indigo? Why must they always be cool colors instead of hot colors. One thing I think would be neat is a skyscr with red gl windows. I would love to see crimson panes with solar film. What do you make of that?