Re: LOGO-L>16 standard colours to RGB

[Michael Tempel <michaelt@media.mit.edu>]

At 1:45 PM -0700 6/25/98, jedwards@hemet.cerf.fred.org wrote:
>
> >Subject - LOGO-L>16 standard colours to RGB
> >Subject - 16 standard colours to RGB
> >I know colour 0 (black) is RGB number [0 0 0] and
>15(white) is
> >[255 255 255].
> >But what are the other RGB-numbers for the 16 standard
>colours.
> >I've got Superlogo.
> >
>Hello,
>
>     The two numbers and their corresponding colors that
>you provided match the standard color codes for Lo-Res
>graphics for the Apple //.  The key to your RGB-numbers is
>the zero to 255 range.  The system is based on the number
>256 and there are 16 colors.  While sixteen does go evenly
>into 256, zero is counted as the first color; so divide 255
>by 15.  These should be your RGB-numbers:
>
>Code    RGB-number            Color
>----    -------------         -------------
>0       [0 0 0]               BLACK
>1       [17 17 17]            MAGENTA
>2       [34 34 34]            DARK BLUE
>3       [51 51 51]            VIOLET
>4       [68 68 68]            DARK GREEN
>5       [85 85 85]            GRAY 1
>6       [102 102 102]         MEDIUM BLUE
>7       [119 119 119]         LIGHT BLUE
>8       [136 136 136]         BROWN
>9       [153 153 153]         ORANGE
>10      [170 170 170]         GRAY 2
>11      [187 187 187]         PINK
>12      [204 204 204]         GREEN
>13      [221 221 221]         YELLOW
>14      [238 238 238]         AQUA
>15      [255 255 255]         WHITE
>

I don't think the above information is correct.

It is true that [0 0 0] is black (lowest intesity of each primary color)
and [255 255 255] is white (highest intesity of each primary color). But
the rest of the combinations on the list above are all shades of gray.

If the three numbers are equal you have some shade of gray.  An intense red
would be [255 0 0], full intensity of red with no green or blue.  Similarly
[0 255 0] is green and [0 153 0] is a darker green.  [255 0 102] is purple
with a redish emphasis, a megenta, etc.

This system gives you 16,777,216 possible colors (256*256*256) but not all
computers can display that many.

I don't know the values for the 16 colors, but except for white, black,
gray1, and gray2, they have to be combinations where the three numbers are
not equal.

-Michael



--------------------------------------------------------
Michael Tempel                    tel: 212 579 8028
Logo Foundation                   fax: 212 579 8013
250 West 85th Street              michaelt@media.mit.edu
New York  NY 10024
http://el.www.media.mit.edu/logo-foundation/


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