Universal file icons
Computer file icon sets are typically for only a limited number of filetypes which often exclude rare or unusual filetypes. Whereas here a universal file icon set that will work with any and all filetypes can be defined as follows.
assigning 3-character file extensions
Begin by truncating every file extension to the first three characters. This will create some conflicts such as not being able to distinguish between DOCX and DOCM but since the purpose of the file icons is to indicate what application you might need to open the file, as opposed to the specific filetype, this should not significantly detract from the visual semantics of the assigned file icons.
One-letter and two-letter file extensions are represented here as three-letter file extensions by adding trailing zeros: M files are represented as "M00" and 7Z files are represented as "7Z0".
character mapping
Each character from 0 to Z now represents a three-digit hexatrigesimal (base-36) number. Each hexatrigesimal integer from 0 to A has to then be assigned an integer decimal (base-10) value from 0 to 255. These decimal integers are then equal to the values of 0 to FF in hexadecimal (base 16).
| base-36 number | base-10 number | base-10 color | base-16 color |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 1 | 1 | 7 | 7 |
| 2 | 2 | 15 | F |
| 3 | 3 | 22 | 16 |
| 4 | 4 | 29 | 1D |
| 5 | 5 | 36 | 24 |
| 6 | 6 | 44 | 2C |
| 7 | 7 | 51 | 33 |
| 8 | 8 | 58 | 3A |
| 9 | 9 | 66 | 42 |
| A | 10 | 73 | 49 |
| B | 11 | 80 | 50 |
| C | 12 | 87 | 57 |
| D | 13 | 95 | 5F |
| E | 14 | 102 | 66 |
| F | 15 | 109 | 6D |
| G | 16 | 117 | 75 |
| H | 17 | 124 | 7C |
| I | 18 | 131 | 83 |
| J | 19 | 138 | 8A |
| K | 20 | 146 | 92 |
| L | 21 | 153 | 99 |
| M | 22 | 160 | A0 |
| N | 23 | 168 | A8 |
| O | 24 | 175 | AF |
| P | 25 | 182 | B6 |
| Q | 26 | 189 | Bd |
| R | 27 | 197 | C5 |
| S | 28 | 204 | CC |
| T | 29 | 211 | D3 |
| U | 30 | 219 | DB |
| V | 31 | 226 | E2 |
| W | 32 | 233 | E9 |
| X | 33 | 240 | F0 |
| Y | 34 | 248 | F8 |
| Z | 35 | 255 | FF |
file icon colors
Each three-character file extension from 000 to ZZZ now represents one of 363 = 46656 possible colors from #000000 to #ffffff.
There are still a few problems here, primarily that most file extensions do not contain decimal number characters so about 10/36 = 28% of available colors are under-utilized. The base-36 color space from 0 to Z could be contracted to just base 26 from A to Z but then the characters 0 to 9 will need to be assigned letters.
| filetype | hexcolor | color |
|---|---|---|
#000000
|
||
| 7Z | #33ff00
|
|
| HTM | #7cd3a0
|
|
#b65f6d
|
||
| SVG | #cce275
|
|
| TXT | #d3f0d3
|
|
| XLS | #f099cc
|
|
| ZZZ | #ffffff
|