How many colors blender has?
I believe that any software have colors in RBG format.
In 3 channels have 256 levels of tones.
256^3=16 millions of colors.
The Blender have 3 channels of 100 levels of tones.
100^3=1 million of colors.
This means a reduction of 1:16 in the amount of colors.
I am certain?
Why not 256 levels of tones ?
Whats wrong ?
Where did you get the number 100 from? I can choose 1000 values for each red, green, and blue.
1000^3 = one billion dollars i mean colors.
You’re limited only by image format and the medium on which the image is viewed
There is nothing wrong.
Vertex colors are stored as 4 bytes (8bits * 4channels = 32bits per color) This is probably all you need.
Material colors are stored as 3 floating point values (32bits * 3channels = 96 bits per color). If you count alpha, material colors have 128 bits of precision. This is a huge range for colors.
I didn’t know the number of levels, but I suspected that Blender handled more than 256 levels by color internally.
It’s like this. 256 levels of luminosity per color channel are NOT enough to store the real relative ranges of luminosity in real life. Your eyes handle the diversity by widening or narrowing your iris to allow more or less light in. In computers, this is done by scaling down the color ranges, often logarithmically. The result is believable, but information is lost.
Now, you DON’T have to lose that much color information when you render. Blender can save your renders as OpenEXR, Cineon and HDR images, which can store far greater luminosity variations. If you have an image editor that can deal with these (HDRShop, CinePaint, Photoshop CS1+), then you might want to try those.
HDR images are said to produce fantastic results with Image-Based Lighting, and this is what the big boys use when they want photorealism. Blender implements it through Ambient Occlusion, and Yafray in either of the Global Illumination options.
I believe that any software have colors in RBG format.
Not true. HSV, YUV and CYMK are common alternatives.
The Blender have 3 channels of 100 levels of tones.
At least 1000, for defining colours. For rendering I think there is a 32 bit range.
Yeah, HDR is the way to go if you’re going to worry about this.
12,884,901,888 colors ought to be enough for anybody. 
for now… in ten years, who knows! 
Cineon should be enough. I mean, 64 bit float per color channel?
Oh, wait. It doesn’t include positional info or backface pixels. It´d be a waste of my 3DGA display.