Today's image, to me, looks sort of European. The tight buildings, the bright colors, the street lamps and similar lamps by the doors, just kind of Amsterdam-ish. If you saw only the finished image (that would be the one on the left) you could easily say "nice, they painted the buildings with bright colors". The truth is somewhere between the original and the finished versions. The smaller image (on the right) is directly out of the camera, having been shot in RAW. With Raw, nothing is done to the image "in camera". No White Balance, no color correction, no sharpening, basically no nothing. That's what a RAW image is all about. What you do with it is up to you. It has to be processed or it ends up looking like the "out of the camera" shot. Today's image takes it a little over the top, but it a pretty straight forward processing. The buildings had nice bright colors to start with and all I did was accentuate them. It find out "how" each color was brightened, hit the "read more".
Everything was done with Adjustment Layers. Each time I use Adjustments Layers I do individual colors. The Create New Fill or Adjustment Layer is used six (in this case seven) times. One each for Red, Yellow, Green, Cyan, Blue, and Magenta. I find it easier to concentrate on specific areas of the image and apply as many same color Adjustment Layers as necessary to treat each areas. In the case of today's image there's two Red areas. The Red segment of the building and the bricks lining the ramp. You can do it with one layer and masking using shades of grey. That's so of hit or miss. By masking the two distinct parts the Saturation level two Hue/Saturation Adjustment Layers can be set independent of each other. In the case of today's image the Lightness of the redder layer was brought down to deepen the red. If only one Adjustment Layer had been used, there would have been a compromise. With two red Hue/Sat Adj Layers no compromise was necessary. Each was set to the value needed to achieve the effect desired.
Using individual Hue/Saturation Adjustment Layers in whatever combination is required sounds like doing extra work. It's actually a time saver. As long as you can do a reasonable job making Masks (saving Selections as Alpha Channels) is a very quick way to work.