Update

color.md

@@ -45,7 +45,7 @@ Let's list some of the most common color models/representations (conversions bet
 - **YUV**: Represents color as one "brightness" value (Y) and two "chroma" values (U and V). Taking only the Y channel would give us a grayscale picture, and the additional U and V components give it full color. This has many advantages, for example if we have a three-wire cable carrying YUV signal, black-and-white screens can just take the Y channel and ignore the other two.
 - **YCbCr**: Similar to YUV, mostly used in encoding of digital [video](video.md) because the separation of intensity and chroma channels allows for good lossy [compression](compression.md) by subsampling (using lower resolution for) chroma, while keeping good resolution for intensity (to which our sight is more sensitive).
 - **grayscale**: Straightforward model for "black and white" (or otherwise monochrome) images in which each pixel just has a single *intensity* ("brightness") value.
-- **indexed** ([palette](palette.md)): Not exactly a "model" but rather a computer representation. Indexed color means that that we have some given palette and then each color is represented simply as a whole number that points to the palette (i.e. color is an index). Colors in the palette can be represented in any model and color depth, for example 24 bit RGB -- the advantage is that representation of a color (i.e. each pixel) can take relatively small space, depending on how many colors there are in the palette (e.g. with a 256 color palette each pixel will only require 8 bits).
+- **indexed** ([palette](palette.md)): Not exactly a "model" but rather a computer representation. Indexed color means that we have some given palette and then each color is represented simply as a whole number that points to the palette (i.e. color is an index). Colors in the palette can be represented in any model and color depth, for example 24 bit RGB -- the advantage is that representation of a color (i.e. each pixel) can take relatively small space, depending on how many colors there are in the palette (e.g. with a 256 color palette each pixel will only require 8 bits).
 - other ones: BGR (RGB with different order of components), HCL (hue, chroma, luminance), HCV (hue, chroma, value), ...
 
 Now given a model such as RGB, a mathematician will like to represent each of the components as a [real number](real_number.md) in the range between 0 and 1, i.e. for example the red color would be represented as [1,0,0]. As programmers, however, we'll eventually have to quantize the values and thus we have to also talk about so called **color depth**, a value saying how many [bits](bit.md) we allocate for a color representation -- the term *bits per pixel* (BPP) is frequently encountered as a unit here. For example the standard for the RGB model is nowadays 8 bits per component, i.e. 24 bits in total, and so it is sometimes called RGB24 (this frequently gets extended to RGB32 by adding another 8bit alpha component, which expresses transparency; this is convenient as 32bit values nicely align in memory). 24bit RGB values are commonly expressed in hexadecimal where, very conveniently, each pair of digits represents one component: for example the color green might be written as `#00ff00` (sometimes even shorter forms are allowed, e.g. [CSS](css.md) also supports `#0f0`). Color depth, naturally, will imply how many colors in total we'll be able to represent. Some devices possess higher color depth (see mainly [HDR](hdr.md)) and some have lower (e.g. [RGB332](rgb332.md) uses 8, [RGB565](rgb565.md) uses 16 etc.). In case we can't split the number of bits evenly, we should allocate more bits for the components that "matter more" in terms of human vision -- for example [RGB565](rgb565.md) allocates 5 bits to red and blue and 6 bits to green, as human eye is most sensitive to green. Especially with lower color depths tricks such as [dithering](dithering.md) can be used to visually simulate more colors.
@@ -65,6 +65,7 @@ The following is a table of some common colors:
 | black        | 0   | 0   | 0   | 1  | 1     | 1    | 0   | 0    | 0     | 0     | 0   | 0    | 0       |`000000`|`0000`| `00` | lack of light, complementary to white                                     |
 | red          | 1   | 0   | 0   | 0  | 1     | 1    | 0   | 1    | 1     | 1     | 1   | 0.5  | 0.29    |`ff0000`|`f800`| `e0` | ~685 nm, RGB primary, complementary to cyan                               |
 | orange       | 1   | 0.5 | 0   | 0  | 0.5   | 1    | 0.08| 1    | 1     | 1     | 1   | 0.5  | 0.59    |`ff8000`|`fc00`| `f0` | ~605 nm, RGB tertiary, AKA light brown                                    |
+| azure        | 0   | 0.5 | 1   | 1  | 0.5   | 0    | 0.57| 1    | 1     | 1     | 1   | 0.5  | 0.44    |`0080ff`|`041f`| `13` |                                                                           |
 | yellow       | 1   | 1   | 0   | 0  | 0     | 1    | 0.16| 1    | 1     | 1     | 1   | 0.5  | 0.88    |`ffff00`|`ffe0`| `fc` | ~580 nm, RGB secondary, complementary to blue                             |
 | green        | 0   | 1   | 0   | 1  | 0     | 1    | 0.33| 1    | 1     | 1     | 1   | 0.5  | 0.58    |`00ff00`|`07e0`| `1c` | ~532 nm, RGB primary, complementary to pink                               |
 | cyan         | 0   | 1   | 1   | 1  | 0     | 0    | 0.5 | 1    | 1     | 1     | 1   | 0.5  | 0.7     |`00ffff`|`07ff`| `1f` | ~512 nm, RGB secondary, complementary to red                              |
@@ -83,10 +84,11 @@ The following is a table of some common colors:
 | brown        | 0.5 | 0.25| 0   | 0.5| 0.75  | 1    | 0.08| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.29    |`804000`|`8200`| `88` | AKA dark orange                                                           |
 | dark yellow  | 0.5 | 0.5 | 0   | 0.5| 0.5   | 1    | 0.16| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.44    |`808000`|`8400`| `90` |                                                                           |
 | dark green   | 0   | 0.5 | 0   | 1  | 0.5   | 1    | 0.33| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.29    |`008000`|`0400`| `10` |                                                                           |
-| dark cyan    | 0   | 0.5 | 0.5 | 1  | 0.5   | 0.5  | 0.5 | 0.5  | 1     | 1     | 0.5 | 0.25 | 0.35    |`008080`|`0410`| `12` |                                                                           |
+| teal         | 0   | 0.5 | 0.5 | 1  | 0.5   | 0.5  | 0.5 | 0.5  | 1     | 1     | 0.5 | 0.25 | 0.35    |`008080`|`0410`| `12` | AKA dark cyan                                                             |
 | dark blue    | 0   | 0   | 0.5 | 1  | 1     | 0.5  | 0.66| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.05    |`000080`|`0010`| `02` |                                                                           |
 | dark violet  | 0.25| 0   | 0.5 |0.75| 1     | 0.5  | 0.75| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.13    |`c00080`|`4010`| `42` |                                                                           |
-| dark pink    | 0.5 | 0   | 0.5 | 0.5| 1     | 0.5  | 0.83| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.2     |`800080`|`8010`| `82` |                                                                           |
+| purple       | 0.5 | 0   | 0.5 | 0.5| 1     | 0.5  | 0.83| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.2     |`800080`|`8010`| `82` | AKA dark pink                                                             |
+| indigo       | 0.3 | 0   | 0.5 | 0.7| 1     | 0.5  | 0.75| 0.5  | 1     | 1     | 0.5 | 0.25 | 0.18    |`4b0082`|`4810`| `42` |                                                                           |
 
 ## Code And Conversions