Color
Everyone likes colors and even can tell the reason to use colors on the web. So you may wonder why we are keeping one full section for colors? We will try to find out the technical reasons for using colors on the web.

Why to use Color?
Using colors in the print industry is difficult job. To produce the consistent color is a matter of long practice and proficiency. We will be discussing the color for web technology. Before we continue further many of you might have observed that there are different types of monitors and resolutions hence the same image can look different on different monitor. So it is a different type of adjustment then the print industry when web is concerned. Web designer tries to use effective color schemes, which goes along with the subject of the web. This area is very sensitive as it can take the web high or completely destroy with wrong color schemes.
If you decorate your web with amazing quality pictures, it may make your page heavy to download. There are limitations of using images on the web till today. Besides use of image also depends upon the subject you are working with. There are some exceptions where you have to use big images. At that time thumbnails comes for your help. Colors can help to make your web appealing. It expresses the feeling of the subject. It can take the content high if it merges with the subject. Color comes with its associations and there is a lot of scope for experimentation with different subjects. Designers have to take the associations of color into consideration for proper output.
There are many other general reasons for the use of colors. The main is, color communicates. It's a very powerful inexpensive tool to put you message forward. By using the proper colors you increase the chances of making your web content prominent and getting more hits.


What is Color?
Everyone can use colors for web but to use colors effectively is a skill. So first, what is color? All that is visible is color; Aristotle said. There can be many definitions of the colors. Defining color accurately is bit tricky because it is not an objective property of nature or a substance. It's related with vision. It is a perception that occurs in living being. Color changes according to the perceptions of the observer. But the different definitions are interesting.

For Artist, color is an artistic way to the world of the human experience, which cannot be described.
To a physicist, color is a phenomenon of waves and particles.
For Chemist, it is a characteristic of molecules.
To marketing executive it is a powerful tool, which can be used effectively for his make, believe profession.
For web page designer it is a fastest way of expressing the heart of the subject on which he is working.
For desktop publisher it is a tool for making communicative layouts.
From the ancient time, the color has been use as a part of object.

It is a means to express the feelings and imagination. It is used wit the same intensity either arts or religion to explore the object to its maximum potential. Great artist like Leonardo da Vinci tried out new pigments with special ingredients to make the color more durable in terms of its luster and age. It is essential to know about color basics to use the colors powerfully on the computers. Especially when you have a program like Photoshop in your hand, which has tremendous potential to create astonishing effects.


Origin of the Color
What is the origin of the color? What is the physiology of human vision? When we see something, what exactly it means? We need to go to some scientific experiments to find out the answers of these questions.

It was Sir Isaac Newton who experimented with the colors and the origin of the colors in 1666. He concentrated on the nature of spectrum we find in the rainbow for his experiment. He achieved the same spectrum when he passed a beam of sunlight through a glass prism. Newton named these colors red, orange, yellow, green, blue, indigo, and violet. Another experiment was carried out by passing a spectrum through glass prism. The output came in the form of white light. The experiments were going on and the third was about the complementary colors. With the help of two prisms he produced different colors on the same spot having white background. The combinations of these colors were producing the color, which lies between two source colors in the spectrum. Isaac Newton came to some amazing conclusions after these experiments.
1. Color is not in the glass it is in the light
2. White light is a mixture of all the colors of the spectrum

Then comes the property of illusion. It is called metamerism. Newton described this property where two colors look identical when viewed under certain light source but it looks different under different source of light.

In 19th century, Physicist James Clerk Maxwell discovered the fact that mixing just three light sources - red, green and blue, can produce wide range of colors. Computer monitors runs on the same principle of producing color from these three light primaries.


Human Vision
You are seeing mango. How your eyes see it? What is the functioning behind it? Color is in light. If we check out sunlight, it is colorless, but as we have seen, when passed through prism gives spectrum. So let us take the example of mango. The functioning of vision takes place as follows.
Light falls from the source (the sun) on the object (the mango) and then it goes to the human eye.
The sunlight shines the mango.
All the colors in the sunlight are absorbed by the yellow surface of the mango except those related with yellow, and reflected to human eye.
The eye receives the reflected yellow light from the object (the mango) and sends message to the brain.

Color Models
Before understanding color models, it is essential to understand different systems. Many of us are aware of the colors as paints. Hence when we mix blue and yellow, we get the shade of green. But the result will be different if we mix green and red light. It will create yellow if 100% red and green light are mixed. So let us understand these two different properties. If we consider the colors produced by the monitor, the light beams generate it. It is based on the RGB model and it is additive color model. Then comes to paint or printing inks. This is based on CMYK model, which is subtractive color model.

RGB Model
Computer creates the colors based on RGB model. It produces spectrum of visible light. Monitor can create millions of colors by combining different percentages of three primaries, red, green and blue. While using the image processing software like Photoshop you can see that these RGB colors are added with the help of numerical value, which is between 0 to 255. With RGB, mixing of red and green equally gives yellow, mixing of green and blue creates cyan and the mixing of red and blue creates magenta. When all the three colors, red, green and blue are mixed equally they produces white light. Hence it is called Additive color model. Another RGB model based example is human eye itself and scanners.
The basic advantage of RGB model is; it is useful for full color editing because it has wide range of colors. But at the same time this model is said to device dependent. It means the way colors displayed on the screen depends on the hardware used to display it.

CMYK Model
Opposite model of RGB is CMY. Printing inks are based on this model. With the full presence of cyan, magenta and yellow we get black. But practically in the printing industry it is impossible to create black with these three colors. The result of the mixture of CMY is muddy brown due to the impurities of the printing inks. Hence black ink is added to get solid black. The outcome of this process CMYK model and k stand for black color, which is also recognized as 'key' color. Since black is a full presence of color, you will have to subtract the levels of cyan, magenta and yellow to produce the lighter colors. This can be explained in different way. When light falls on the green surface or green ink. It absorbs (subtracts) all the colors from light except green. Hence the model is called subtractive model. Print production is based on this model.

It is useful to have proper understanding of the color models. The monitors as well as scanner works on RGB principle. While scanning we can adjust the software to produce desired result. CMYK is for print industry. It cannot produce the color range of RGB hence after finishing the work on computer in RGB mode when you convert it into CMYK for printing some tonal changes can be occurred. In spite of its limitation CMYK model is considered as best model available for printing because it can produce properly finished output.

Spot & Process Colors
Before going into the details of the subject let us understand the way of printing. If you have certain printing job to be done you have to decide what type of color printing you will go for. And the decision depends upon many factors like, type of job, cost effectiveness, necessity etc. You have two options available for printing any type of job in color.

1. Spot color
2. Process color

Spot Color
Whenever you require some particular color, it is advisable to choose spot color method. If the job is corporate logo, where the precision of the color is top most priority, you have to go for spot color. Spot color is also known as custom color because it is premixed to the desired color or the shade of the color prior to printing. Next is a type of job you want to print. If it requires one or two colors, the obvious choice will be spot colors. At that time is the most cost effective method. Then there are some colors which cannot be created by mixing process inks, like silver, copper etc. For this type of work the spot color method is unavoidable.

Process Color
If the printing job is a full color photograph or if the job requires more then three colors, process color is advisable. Process colors are made by mixing the levels of CMYK i.e. Cyan, magenta, yellow and black to get thousands of colors, which are sufficient to produce smooth colored photograph. Sometimes in the printing job both the methods are used. You may observe this in the brochures where the photographs are printed with process colors and the corporate logos are done with spot colors, as it requires exact mach.

Halftones
Check out your newspaper. You will find smooth photographs but if you watch them closely you will observe that they are made up of small black dots of different sizes. This property of creating continuous tone with black dots is called Halftoning.

To process the photograph it has to be converted into dots, which is called halftoning process. The dots are created as follows.

The bright area, which is known as Highlights in image processing, contains more white space with few small black dots. The gray area, which is known as Midtones, contains medium sized black dots. The dark area, which is known as Shadows, contains large black dots with less white space.

These dots are arranged in a proper order. Traditionally they are organized in a row per so many inches at predefined angles.

Using halftoning process it is possible to create smooth gray tones with gray tint by controlling the arrangement of black and white areas. While working with photographs, it is possible to create smooth tones using proper size of dots.

This web article was provided by http://www.orionnetlinks.com The place of designing solutions.

Thanks for reading.