Red
Danger, importance, passion
Red is one of the most powerful colors, it can show the hot love, also can reflect the tragic war. In English, "to see red", Chinese in the "red" can be a good reflection of the color contained in the emotional color.
In general, the red element is more easily noticed, and its emphasis makes it more important to use this color, which is, of course, a hint or a warning, whether good or bad is another question.
Both Netflix and YouTube use red as their main color.
Red can be used as a warning color, the natural life of a warning red fur, indicating stop and warning traffic lights are red. But the meaning of the red will vary according to the occasion, dosage and design. A small amount of red can often be a good highlight, and overuse may make the atmosphere seem less relaxed.
The red "Delete" button appears to be a cautionary tale compared to the "Cancel" button.
On the other hand, red is closely associated with "heat".
Smart home equipment Nest use red to indicate heating mode.
Orange
Confidence, energy, optimism
And red as the warm color of Orange also has an "incentive" side, but the degree of relatively lighter. Orange is not as aggressive as red, but equally vibrant, Orange is often found in health-related situations, such as vitamin C (which, of course, is inseparable from vitamin-rich oranges).
The poster of Orange for telecom operator
Orange is playful and optimistic, very suitable for appearing in the leisure place. But for businesses, Orange is not the color of choice, and research has shown that orange can give people a cheap feeling. However, Hipmunk has a good use of orange based on its own color scheme. Whether it's cheap or not, a CTA button with a significant effect is always noticeable on a blue-white page.