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ORGANIZATIONAL CHARTS
"NON-DITHERING" COLORS

Everyone who wants to introduce color in their e-mail or signature and webpages soon comes to learn that there are two ways to do so: either by naming a color or by specifying a HEX CODE. Easy enough to go to a link such as the one just given, look at the colors and choose to use one specification or the other. To understand, though, how the HEX codes for colors are differently distinguished is helpful, for the actual full range of colors that can be represented by HEX codes is not realizable nor practical.


What are HEX codes?


Colors in HTML may be given by a six digit HEX code of the form ######. Each pair of digits, ##, may be said to represent gradations in the three primary colors red, green, and blue (RGB). Choosing a pair of digits for each of these primary colors in a HEX code can be viewed as "mixing" RGB gradations to give another particular color.

Non-dithering colors are colors that do not change from what was originally intended upon being viewed from different browsers. These practical HEX codes consist of only 3 pairs of digits for each of the primary colors:


00336699ccff


This is very convenient, at least for organizational purposes, since it means that any 2 pairs of HEX codes can have all possible arrangements given by a table:


 00336699ccff
00000000330066009900cc00ff
33330033333366339933cc33ff
66660066336666669966cc66ff
99990099339966999999cc99ff
cccc00cc33cc66cc99ccccccff
ffff00ff33ff66ff99ffccffff


This is a 6x6 table, so there are 36 cells in this table. To introduce the 3rd set, place the HEX pair of digits, 00, before the 2 HEX pairs in each cell and there is obtained a table for all colors whose HEX code begins with 00. Do the same for 33, 66, and so on and there is obtained 6 tables of HEX codes for all 216 non-dithering colors. These are given below:


 00336699ccff
000000000000330000660000990000cc0000ff
330033000033330033660033990033cc0033ff
660066000066330066660066990066cc0066ff
990099000099330099660099990099cc0099ff
cc00cc0000cc3300cc6600cc9900cccc00ccff
ff00ff0000ff3300ff6600ff9900ffcc00ffff


 00336699ccff
003300003300333300663300993300cc3300ff
333333003333333333663333993333cc3333ff
663366003366333366663366993366cc3366ff
993399003399333399663399993399cc3399ff
cc33cc0033cc3333cc6633cc9933cccc33ccff
ff33ff0033ff3333ff6633ff9933ffcc33ffff


 00336699ccff
006600006600336600666600996600cc6600ff
336633006633336633666633996633cc6633ff
666666006666336666666666996666cc6666ff
996699006699336699666699996699cc6699ff
cc66cc0066cc3366cc6666cc9966cccc66ccff
ff66ff0066ff3366ff6666ff9966ffcc66ffff


 00336699ccff
009900009900339900669900999900cc9900ff
339933009933339933669933999933cc9933ff
669966009966339966669966999966cc9966ff
999999009999339999669999999999cc9999ff
cc99cc0099cc3399cc6699cc9999cccc99ccff
ff99ff0099ff3399ff6699ff9999ffcc99ffff


 00336699ccff
00cc0000cc0033cc0066cc0099cc00cccc00ff
33cc3300cc3333cc3366cc3399cc33cccc33ff
66cc6600cc6633cc6666cc6699cc66cccc66ff
99cc9900cc9933cc9966cc9999cc99cccc99ff
cccccc00cccc33cccc66cccc99ccccccccccff
ffccff00ccff33ccff66ccff99ccffccccffff


 00336699ccff
00ff0000ff0033ff0066ff0099ff00ccff00ff
33ff3300ff3333ff3366ff3399ff33ccff33ff
66ff6600ff6633ff6666ff6699ff66ccff66ff
99ff9900ff9933ff9966ff9999ff99ccff99ff
ccffcc00ffcc33ffcc66ffcc99ffccccffccff
ffffff00ffff33ffff66ffff99ffffccffffff


These 6 color tables represent slices made through a color cube. If one was able to view this as if the cube was transparent the entire kaleidascope of non-dithering colors would be seen on the faces and throughout the cube.

It is instructive and informative to now view each pair of HEX codes for a color as representing a particular value for R, G and B, as in the RGB representation of colors. Here the 256 possible shades of R, G, and B are each assigned a number from 0 to 255. Using the color cube values, though, only 6 shades of R, G, and B are considered.

How these are to be used is readily illustrated by generating the shades of gray between white, ffffff, and black, 000000. It will be noted that equal values of R, G and B must pertain. There is thus obtained:


Grays
333333
666666
999999
cccccc
ffffff


If all 16 HEX codes were used in this way there would be a steady progression of shadings going from black to white.

The darker primary color shades for RGB are obtained by "blacking-out",i.e,setting as 00, the other primary colors. The lighter shades are gained by "whiting-out", i.e.setting as ff, the chosen primary and combining the other two.


 
Reds
330000
660000
990000
cc0000
ff0000
 
Greens
003300
006600
009900
00cc00
00ff00
 
Blues
000033
000066
000099
0000cc
0000ff


 
ff0000
ff3333
ff6666
ff9999
ffcccc
Reds
 
00ff00
33ff33
66ff66
99ff99
ccffcc
Greens
 
0000ff
3333ff
6666ff
9999ff
ccccff
Blues


Here too use of all 16 HEX codes would lead to a progression of the primary colors going from their darkest to their lightest shade. This progression is plainly seen using other sets of HEX codes, as shown below.


000000
330000
660000
990000
cc0000
ff0000
000000
003300
006600
009900
00cc00
00ff00
000000
000033
000066
000099
0000cc
0000ff


333333
663333
993333
cc3333
ff3333
333333
336633
339933
33cc33
33ff33
333333
333366
333399
3333cc
3333ff


666666
996666
cc6666
ff6666
666666
669966
66cc66
66ff66
666666
666699
6666cc
6666ff


999999
cc9999
ff9999
999999
99cc99
99ff99
999999
9999cc
9999ff


cccccc
ffcccc
cccccc
ccffcc
cccccc
ccccff


Any two primary colors can be "mixed" or combined in just as consistant a progression by "blacking-out", i.e., setting as 00, the third. And as before, the lighter shades are gained by "whiting-out", setting as ff, the primary colors that are combined. Again, all 16 HEX codes could have been used for this illustration.


 
Yellows
333300
666600
999900
cccc00
ffff00
 
Cyans
003333
006666
009999
00cccc
00ffff
 
Magentas
330033
660066
990099
cc00cc
ff00ff


 
ffff00
ffff33
ffff66
ffff99
ffffcc
Yellows
 
00ffff
33ffff
66ffff
99ffff
ccffff
Cyans
 
ff00ff
ff33ff
ff66ff
ff99ff
ffccff
Magentas


Even at this early stage it is evident that the color cube describes not so much color, there being only 6 differing colors, but shades of these colors. It is also plain that all 16 of the HEX code pairs can be used for them and their shadings. The choice of only 6 pairs of HEX codes is no more and no less than an expedient. There is nothing "magical" to the non-dithering nature of these 6 pairs, all 16 pairs meet the same criteria. They designate the intensity for the R, G and B color beams of a TV or monitor. Dithering will take place if these beams are out of balance, a common occurence. Otherwise they are non-dithering.

Continuing the "mixing" of color pairs provides alternative shade groupings. Less than 6 HEX codes are used when an abrupt color change takes place, designating a cross-over to another color domain.


 
ffcc00
ffcc33
ffcc66
ffcc99
 
00ccff
33ccff
66ccff
99ccff
 
cc00ff
cc33ff
cc66ff
cc99ff






This section may be difficult for some as it does entail a mathematical construct. Continue if desired, but otherwise return to the more general information.


BACK
Bits and Bytes


A BIT is a switch that can be either 0 or 1, i.e., it has 2 different settings. Many systems use BYTEs consisting of 4 bits. So 4 bits can represent 2 x 2 x 2 x 2 or 16 different bytes.

HEXadecimal
Control & Character Equivalents


With 2 bytes independent of one another 16 x 16 different things can be represented, e.g., keyboard characters, typewriter operations such as space or return, or cursor/screen commands such as cursor home or scroll. Making a checkerboard-like table 16 items across (a row, r) and 16 items down (a column, c), each "thing" can be identified by rc, its HEX CODE according to which row and which column it may be in. Labeling the 16 items across and down by 0 to 1 AND a to f gives hex codes as are usually seen, e.g., 76, 0d, or ea. These are often used as a type of machine language.

Numbering the cells in a sequential manner gives an ASCII sequence table which identifies all characters and typewriter operations possible on a typewriter keyboard, including those characters obtained using special keys like "cmd" and "alt". Additional symbols and characters are to be found in an extended ASCII table or a table for ctrl or alt sequences. All of these have HTML codes known as HTML-equivalents.

Colors


Consider the Red, Green, Blue (RGB) representation of color. Each of these is given a number from 0 to 255 going from when the color "looks" blackest to when it "looks" whitest. Mixing RGB gives any visible color desired, just as with a color TV set. So there are actually 256x256x256 (some millions) of possible colors and shadings of color.

Why the number 256? It has to do with bits (on-off switches) and bytes (collections of these). For a set of 4 bits there are 16 ways of having on-off for them. With 2 sets of 4 there are 16x16 ways (bytes), i.e., 256 ways. All possibilities can be represented as a table with rows and columns labeled:

         0 1 2 3 4 5 6 7 8 9 a b c d e f

There are 16 of these, so it is termed a HEXadecimal representation.

To identify any one cell just give the HEXadecimal value corresponding to the row and column it is in, e.g., 4f, a5, 88, or bb. The RGB system just labels the cells sequentially for R, G, and, B, i.e., 1 for 00 , 2 for 02, going to 256 for ff.

The 216 base colors often referred to applies ONLY to those RGB HEX codes for which the HEX representation is every 3rd one and the same, i.e., 00, 33, 66, 99, cc and ff. That is only 6 pairs. Three tables of hex codes for are needed for RGB, so taking only these HEX representation, to specify a color three PAIRS of hexadecimal values are needed; for example 00 cc aa, which is what is usually done in HTML.

All possible combinations of ONLY these HEX code colors can be made by creating a table of, say, G and B combinations for which the rows and columns would be labeled:

                                    00 33 66 99 cc ff

There are here 6x6 or 36 such cells. Putting the 1st HEX value for R in every cell of this, then the 2d, and so on gives 6x36 or 216 possible colors. In a 3-D (x,y,z-axis) representation this would be a cube, so it is called the 216 color-cube. It is also a selection of "non-dithering" colors, i.e., the color selected will show up the same independent of the type of browser and will not be viewed a different color than intended. This is the basis for Beth's background color chart. These can also be specified by a name rather than a hexcode.

What about the other colors?? These are the ones most often found named. Their hex code PAIRS for RGB are the same,e.g., 2f 66 3d.

Even if this explanation is not entirely understood by the viewer perhaps an idea has been gained of why things with most computers are just 16s or multiples thereof, e.g., 16 or 32 bit processors or 256 base HEX character equivalents.


BACK



Page writen and designed by: Art C.
Used with permission
Thank's Art.


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