Colors & Codes

Colors & Codes#

Reference of color-encoding standards an operator works with, ANSI / xterm terminal palettes, web color models, paint classifications, and adversary / discipline-specific color conventions (TLP, defcon, conditions).

ANSI / terminal escape colors#

Sequence	Color
033[30m	black (foreground)
033[31m	red
033[32m	green
033[33m	yellow
033[34m	blue
033[35m	magenta
033[36m	cyan
033[37m	white
033[90m	bright black (gray)
033[91m	bright red
033[92m	bright green
033[93m	bright yellow
033[94m	bright blue
033[95m	bright magenta
033[96m	bright cyan
033[97m	bright white
033[40m…033[47m	background colors (matches foreground codes)
033[100m…033[10	7m bright background.
033[38;5;Nm	256-color foreground (N = 0-255).
033[48;5;Nm	256-color background.
033[38;2;R;G;Bm	24-bit truecolour foreground.
033[48;2;R;G;Bm	24-bit truecolour background.
033[0m	reset.
033[1m	bold.
033[2m	dim.
033[3m	italic.
033[4m	underline.
033[5m	blink (rare).
033[7m	reverse video.
033[9m	strikethrough.

Web / HTML color#

Form	Notes
Hex 6-digit	`#RRGGBB`; `#FFAA00` = orange.
Hex 3-digit	`#RGB`; expanded to `#RRGGBB`.
Hex 8-digit	`#RRGGBBAA`; with alpha.
`rgb()`	`rgb(255, 170, 0)` or `rgb(255 170 0)` (CSS Color 4).
`rgba()`	`rgb(255 170 0 / 50%)` modern syntax.
`hsl()`	hue (0-360°) saturation lightness.
`hwb()`	hue whiteness blackness.
`lch()`, `oklch()`	perceptual color spaces; CSS Color 4.
`color()`	per-color-space (sRGB, display-p3, rec2020, …).
`color-mix()`	CSS Color 5; mix two colors.

CSS named colors (selection)#

Name	Hex
black	#000000
white	#FFFFFF
red	#FF0000
lime	#00FF00
blue	#0000FF
yellow	#FFFF00
cyan / aqua	#00FFFF
magenta / fuchsia	#FF00FF
silver	#C0C0C0
gray	#808080
maroon	#800000
green	#008000
navy	#000080
purple	#800080
orange	#FFA500
crimson	#DC143C
gold	#FFD700
indigo	#4B0082
teal	#008080
olive	#808000
salmon	#FA8072
coral	#FF7F50
khaki	#F0E68C

There are 147 CSS named colors from CSS Color 4. rebeccapurple (#663399) was added in 2014 in memory of Eric Meyer’s daughter.

Pantone / industrial systems#

System	Notes
Pantone PMS	spot color reference for printing.
RAL	European industrial / signage color.
NCS	Natural Color System (Scandinavia).
Munsell	scientific color-classification.
Federal Std 595	US gov color standard (FED-STD-595B/C).
BS381C	UK British Standard.
JIS Z 8721	Japanese industrial.

Cybersecurity / threat color conventions#

Convention	Notes
TLP	Traffic Light Protocol; sharing constraints: TLP:CLEAR (formerly WHITE), unrestricted. TLP:GREEN, community-wide. TLP:AMBER, limited; on a need-to-know. TLP:AMBER+STRICT, recipient’s org only. TLP:RED, named recipients only.
DEFCON	US DoD readiness states (5 normal, 1 max alert). See conditions below.
HPCON	Health Protection Condition (DoD pandemic).
INFOCON / CYBERCON	US DoD info-ops conditions; 1 (highest) -> 5 (normal).
HSAS	US Homeland Security Advisory (deprecated 2011); was Green / Blue / Yellow / Orange / Red.
NTAS	successor to HSAS; Bulletin / Elevated / Imminent.
US Threat Levels	UK MI5: Low / Moderate / Substantial / Severe / Critical. AU: Negligible / Low / Probable / Expected / Certain.
DHS / FEMA HazCon	Hurricane condition: 5 normal, 1 imminent landfall.

Other operational color codes#

System	Notes
Hospital codes	Code Blue (cardiac), Code Red (fire), Code White (violent person), Code Black (bomb), Code Pink (infant abduction), Code Silver (active shooter), Code Yellow (mass casualty); per-jurisdiction varies.
Aviation alerts	Notams + ATIS; not color-coded.
Maritime	IALA buoyage: red / green channel-marker schemes; the “red right returning” rule (US / region B) reverses in region A (EU / Africa / India).
Military map / OPS	blue = friendly, red = hostile, green = neutral, yellow = unknown (NATO APP-6).
TSA / FEMA	color-coded baggage tags etc.
US RAM-W	USACE site-vulnerability color scale.
US PROBLEM	lab biosafety: BSL-1 (low) -> BSL-4 (max).

DEFCON levels#

Level	Notes
DEFCON 5	Normal peacetime.
DEFCON 4	Above normal; intelligence watch + measures.
DEFCON 3	Air Force ready in 15 min; greater readiness.
DEFCON 2	Armed forces ready for action in 6 h.
DEFCON 1	Maximum readiness; nuclear war imminent / underway.

The US has only publicly entered DEFCON 2 (Cuban Missile Crisis, 1962; Yom Kippur War, 1973).

Operator notes#

TLP is the standard for CTI sharing; embed in every shared document. Mistakes here are operational, not just cosmetic.
Truecolour terminals are universal in modern terminal emulators; legacy workflows still expect 8 / 16 / 256 color.
WCAG color contrast, 4.5:1 (AA) / 7:1 (AAA) for body text against background.
Color-blind audiences, don’t rely on color alone for meaning; pair with shape / label.
Region B vs A buoyage, US / Canada / Caribbean / Korea / Philippines / Japan use IALA-B (red right returning); the rest of the world uses IALA-A (red left).
No DEFCON color, DEFCON levels are numeric, not color-coded; the “DEFCON color chart” online is fiction.