Red Tulip

Red Ferry

Red Apple

Red Amanita

The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide.

Traffic sign

Most countries post signage, known as traffic signs or road signs, at the side of roads to impart information to road users. Since language differences can create barriers to understanding, international signs using symbols in place of words have been developed in Europe and adopted in most countries and areas of the world.
Traffic sign - Wikipedia, the free encyclopedia

Red - Color symbolism and psychology

Passion, strength, energy, fire, love, sex, excitement, speed, heat, arrogance, ambition, leadership, masculinity, power, danger, gaudiness, blood, war, anger, revolution, radicalism, socialism, communism, aggression, summer, autumn, stop, Mars (planet), respect, Aries (star sign), December.
Studies show that red can have a physical effect, increasing the rate of respiration and raising blood pressure; red also is said to make people hungry; the red ruby is the traditional 40th wedding anniversary gift; red sky in the morning, shepherd's warning; red sky at night, shepherd's delight.
Color symbolism and psychology - Wikipedia, the free encyclopedia

Red is a color

Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 625–750 nm. Longer wavelengths than this are called infrared, or below red and cannot be seen by human eyes.
Red - Wikipedia, the free encyclopedia