Part1
People have wondered about the nature of light and color since ancient times.
Some people thought that light came from the eye rather than coming into the eye.
To see, light was projected（v.规划;计划;拟订方案;预测;预计;推想;放映;投射;投影） from our eyes to illuminate（照明） things as we looked at them.
Now we know that what we see is mostly reflected light, like the light from the moon, which is reflected sun light.
Light comes from a light source such as the sun and either enters our eyes directly or after it has reflected off（反射） something.
In 1666 Sir Isaac Newton showed that when light passes through a prism（三棱镜）, it separates into all the other colors.
This clearly demonstrated that light is composed of many different colors.
The difference between colors is due to their wavelength(波长).
A prism separates light into different colors because each color has a different wavelength.
The angle at which a color bends in a prism depends on its wavelength.
Q: What happens when light passes through a prism?
A:The light seperates into colors.
Q: The angle at which a color bends in a prism...
A: Depends on its wavelength.
Colors with shorter wavelengths bend more than colors with longer wavelengths.
This explains why red light bends less than yellow light.
The reason is because its wavelength is longer.
Of the visible colors, violet light has the shortest wavelength, so it bends the most.
Each color is a single wavelength of light.
A prism separates light into its component colors.
Besides the sun, any objects that produces its own lights is a direct light source.
If you have ever painted you know that different colors can be combined(adj.联合的;共同的;总计的;总共的v.(使)结合，组合，联合，混合;兼有;兼备;使融合(或并存);同时做(两件或以上的事);兼做;兼办) create new colors.
For example if you add white to a color you'll lighten it.
However the three primary colors, red, blue and yellow, cannot be made by mixing other colors.
It isn’t possible to mix any combination of colors to create red, blue or yellow.
Mixing two primary colors creates a secondary color, such as purple, which is made by mixing blue and red.
Mixing three primary colors creates a tertiary(n./adj.第三级;第三系) color, such as brown or grey.
Part2
Colors are wonderful to look at but they also affect people in ways beside sight.
They have a powerful effect on how people feel and behave.
Artists know this and so do business people who want to influence（影响） how people feel about their products and advisements.
For example research has shown that people can be more productive if they are working in a blue room.
The color purple is often linked to wealth or royalty(王权) and is seen as a mysterious spiritual color（神秘的精神色彩）.
Some colors have even been associated with changes in blood pressure.
Though color can influence how we feel and act, these effects may depend on personal and cultural factors（n.因素;要素;因子;因数;(增或减的)数量，倍数 v.把…因素包括进去;（数学）分解…的因子，将…分解成因子;以代理商（或管家等）的身份行事;做代理商（或管家））.
Therefore it’s important not believe everything you hear about the effects of color.
Different colors can be combined to form other colors.
The primary colors cannot be created by mixing other colors.
Purple is made by mixing blue and red.
Some colors have even been associated with changes in blood pressure.
Though there are differences between cultures, there is general agreement（一直认为，普遍认可） about some colors.
The color red, for example, is a warm color associated with energy and excitement in many cultures.
In China red is associated with fire, energy and good fortune（命运，财富）.
On the other hand, one experiment shows that exposing students to red before taking a test can have a negative effect.
In fact, of all the colors, research shows that red has the most powerful effect on human behavior.
Certainly, it’s interesting and important to better understand the cycle logical of facts of light and color.
To gain a better understanding of these effects, more research is needed.
