Arachne COLOR rendition Howto 00/07/31 Written by Clarence Verge Part 1 - The Technobabble: Arachne is pre-programmed to respond accurately to ONLY the original M$ set of standard HTML color names. These colors are a holdover from the limitations imposed by digital (on/off) video signal levels. The three colors Red, Green and Blue can only be combined eight ways in an on/off fashion. If you add one more digital signal representing intensity, this doubles the possibilities to 16. If 0 represents off and 1 represents on, we can get the following IRGB combinations: Intensity Red Green Blue Visual result 0 0 0 0 Black 0 0 0 1 Dark Blue (Navy) 0 0 1 0 Dark Green (Green) 0 0 1 1 Dark Cyan (Teal) 0 1 0 0 Dark Red (Maroon) 0 1 0 1 Dark Magenta (Purple) 0 1 1 0 Dark Yellow (Brown/Olive) 0 1 1 1 Dark White (Gray) 1 0 0 0 Bright Black (Gray) 1 0 0 1 Blue 1 0 1 0 Green (Lime) 1 0 1 1 Cyan (Aqua) 1 1 0 0 Red 1 1 0 1 Magenta (Fuchsia) 1 1 1 0 Yellow 1 1 1 1 White It can be seen that there is a duplicate definition for Gray leaving a spare combination available when these values are translated to levels for analog video (VGA) use. These are the 16 widely known color names with their Hex RGB intensity values. A Hexadecimal value of 00 is off or dark, FF is on maximum or bright, and 80 is on at half intensity. Mostly equivalent to the above: Black = #000000 Green = #008000 Silver = #C0C0C0 Lime = #00FF00 Gray = #808080 Olive = #808000 White = #FFFFFF Yellow = #FFFF00 Maroon = #800000 Navy = #000080 Red = #FF0000 Blue = #0000FF Purple = #800080 Teal = #008080 Fuchsia= #FF00FF Aqua = #00FFFF Here we see that the extra GRAY condition has been raised to SILVER, an intensity a little higher than 1/2 way between gray and white. This would be impossible without the fine variations possible due to the use of an analog video signal. To use this capability further requires the use of SVGA or HiColor. The 4bit combinations can define only 16 colors, 8bit combinations can define 256 colors, and 24 bit combinations as show above where a full eight bits is used for each of R G B, can produce 16.7 million colors. This is called TrueColor. HiColor is a 16 bit mode. It is important to note that except for Hicolor, the second character in each Hex pair has no effect. Taking only the 16 levels specified by the most significant hex digit of each color, a total range of 4096 colors can be specified. (16x16x16) In fact, if you skip every second Hex character in the first digit, it is still possible to specify 512 colors, or twice as many as the 8bit (256 color) video modes support. So, the above Hex HTML color specification must be reduced severely by software to fit the limitations of the video mode. You can pretty much ignore the low nibble character. Part 2 - The Suggestions: Arachne (and the other browsers) respond to color names other than the above standard 16, but not in an easily predictable manner. Some of the big browsers support names like cadetblue or chocolate or even cyan but Arachne renders cyan the way the big boys would render "roadkill". After checking for the "#" character first and the 16 known names next, Arachne takes the first six characters of the color spec. and treats it as hexadecimal whether it is or not. So the word cyan, containing only four characters, will convert to a color without any blue in it. In fact, as pointed out above, the second character has no real effect either on the result, so only the letters "c" and "a" are used. These happen, by chance, to be legal hex characters. Arachne displays yellow for cyan which is almost exactly the opposite to what is intended. The safe approach for both local Arachne use and pages online, is to use only the standard 16 agreed upon color names as far as possible, and for any other required color specification use Hex RGB values. Remember that others may not be viewing anything even close to what YOU might be seeing if you use 24 bit RGB specs, and they CERTAINLY won't see what you intend if you put your Xmas message up in red and green and they view it in monochrome. :( Arachne has a page review capability unparalled by the other browsers. View ARACOLOR.htm to see the effect of video mode on Arachne pallette. Use Video Setup, found on the Aracolor or Options pages to change your video mode and check out your pages. Remember to try a grayscale mode. The top 16 color bars are the 16 standard named colors. On the left in the bottom half you can see the effect of stepping by 2 in intensity for grayscale. You will also probably notice that in *16* color modes purple and fuchsia look the same, and at the bottom there is a gray bar that is brighter than silver (C0C0C0). I don't know yet if this is a bonus color provided by my video boards or an Arachne special. The code I have examined to date shows Arachne translating FUCHSIA to #FF00FF, not #800080 and NO word is coded to be = #E0E0E0. If three colors each having possible intensities of off, on and bright are available, 27 combinations are possible. The bottom right side of ARACOLOR.htm shows most of the 11 combinations that are not used in the standard 16. Take care to note that most of these combinations become indistinguishable from SILVER when a 16 color video mode is used !! Try Arachne in 16 color mode and toggle monochrome with the "!" key. Arachne does not require the color name to be in uppercase and she does not require quotes around color names. She does require the leading "#". Video setup is also useful to see how wide your page looks in 640x480. Press your back button to return to Arachne. 8-)