Warm and cool gray mixes are used to make this exciting scene of a rainy Paris scene. This video a great exercise for how to use grays to support a small percentage of bright colors.
Be sure to check out how I finished the art in the attached download. (Click button below video to view)
Watercolor Notes: work light/bright - to - dark/neutral
1) Plan where your bright lights will be and put in a few 'brights' (yellow, orange, and red) let these colors merge and puddle knowing you can paint over any bright to 'kill the intensity' later with neutrals. Save some white of the paper if possible for your light's center dot. Let dry, or do Step 2 wet-in-wet.
2) Use Burnt Umber and Cobalt or Ultramarine Blue mixes for neutrals in warm/cool shifting puddles. Ultramarine will granulate (texture looks like denim or pebbled) for further atmospheric effects when dry. Allow colors to puddle and merge. Try not to fuss as things dry. See other watercolor demos in the program to further understand water levels, mixes and flowing paint.
3) Restate (paint over when wet) with a rich dark from the above warm/cool mix. Try to keep layers to only 3 (it's difficult to make a true dark in watercolor, maybe use a practice scrap sheet of paper to check your value and color before painting on the artwork).
"Body Color" is an English term for using a small touch of white gouache in watercolor. This is a different technique than full gouache (as is popular currently with artists working today). Full gouache uses a lot of paint, but body color just makes tints and washes velvety and milky. It's great for fog and rain. Trevor Chaimberlain, Edward Seago, John S. Sargent used this technique.
Review the 'Paris Grays Mixes) video in Fundamentals for coaching on how to use tube black, tube gray, and mix your own grays. Use a value scale to check the mixes. Challenge yourself to make only 5% of the painting 'bright' or highly chromatic with vibrant color. By using warm/cool shift to the gray mixes you can create harmony and excitement, even with a drab rainy scene photo for reference.
Try using your own reference. Try a sketch to sort the values first and find the 'big shapes' (very simplified). Make sure you use the tip of 'find the sky shape' versus fretting about perspective. Old cities and narrow streets work well with this tip.