The phrase "rich blues" refers to a deep and vibrant shade of the color blue. It implies that the blue has a strong and luxurious appearance. Full definition
Put together a confident mix of geometric patterns and textured finishes, all in a palette of rich blues with hits of earthy orange. (idealhome.co.uk)
Seeing the navy blue makes me think that we'll be seeing more deep rich blues in home decor. (theinspiredroom.net)
The dying liquid is actually pale purple, and over time a chemical reaction occurs that transforms the final color into the most stunning rich blues. (viktoriastable.com)