// chapter 03

Color

One brand accent. A dark canvas. A separate set of functional colors for system states. Amber never doubles as warning.

Brand accent

amber signal

#FBBF24

CTAs, highlights, coverlines, focus states, glow accents. The only chromatic statement HASL makes.

Dark surface system

Void

#0B0D10

surface 0 · default canvas

Surface

#16191E

surface 1 · cards

Border

#2A2F37

dividers, outlines

Frost

#E8ECEF

text on dark

Light surface system

Used for print, light-mode emails, and documents that need to read on white paper.

Paper

#FAFAF7

light surface 0

Ink

#0A0A0A

text on light

Functional colors — system states only

These are not brand colors. They appear only in system states: form errors, validation warnings, success confirmations, info messages. Never on brand pages, never as accents.

Error

#EF4444

Warning

#F59E0B

(intentionally distinct from Amber Signal)

Success

#10B981

Info

#3B82F6

Don'ts

Never use Amber Signal as a system warning color.
Never introduce a second chromatic accent. Amber does all the talking.
Never tint Void or Surface with hue — they are intentionally neutral.
Never use functional colors (warning, error) on brand pages or marketing.