BlueGray

Blue lowers stress and is associated with trust, intelligence and reliability. It is the color of stability and competence, which is why so many banks, insurers and technology companies build their brands around it.

Blue dominates corporate, financial, healthcare and technology design. Light blues feel airy and clean, while deep blues convey authority and luxury. It is also the default for links and primary buttons in countless interfaces.

Ultramarine was once made from ground lapis lazuli and was more expensive than gold, reserved for the robes of the Virgin Mary in Renaissance art. Prussian blue and synthetic ultramarine later made blue affordable and ubiquitous.

Blue commonly means trust, peace, loyalty and wisdom. In some cultures it is protective, in others it signifies sadness, and it is widely used in flags and institutions to project stability.

Choose blue when you want to build trust, calm and professionalism. It is the safest choice for corporate and financial brands and for interfaces where clarity and reliability matter most.

Against white, #6699CC has a 3.0:1 contrast ratio; against black it is 7.0:1. Black text on #6699CC meets WCAG AA for normal text.

Roughly 180° across the wheel from #6699CC (hue 210°) sits #cc9966, held together by the #c9d9e8 tint and the neutrals #f4f4f5 and #18181b.

#6699CC with its two closest neighbours, #66cccc and #6666cc, for a 50%-saturation run that stays inside one family; #c9d9e8 and #2d5986 add depth without breaking it.

#6699CC plus #cc6699 and #99cc66, a triangle that sits 120° apart at every corner, with #f4f4f5 and #18181b doing the quiet work underneath.

One hue at 5 lightness steps: #f0f5fa through #080f17, starting from #6699CC at 60% lightness.