Rainy scenes for me live in muted
Blues and the quiet warmth of diluted streetlight. I usually start with a base of desaturated navy, slate blue, and charcoal gray to set the overall damp, low-contrast mood. From there I add a few key notes: a deep teal or mossy green for vegetation and reflections, and a soft, warm amber or ochre used sparingly for streetlights, window glows, or umbrella interiors. Those warm accents give the scene a focal point without destroying the rainy
atmosphere.
I like to think in layers: a cool ambient layer (
Bluish-grays), a slightly richer mid layer for saturated reflections (teal,
Indigo), and a thin top layer for highlights (pale cyan, near-white with a hint of blue). Keep saturation low overall and increase saturation only in reflections or neon pops. Also consider violet or mauve as a subtle secondary color if you want a
Twilight feel. Wet surfaces mirror local colors, so let puddles borrow both the cool sky tones and the warm artificial lights — that interplay sells the rain, at least for me.