Substack vs OpenAI
54 token-level differences between these two design systems.
Background
#ffffff → #ffffff Text
#363737 → #000000 Brand
#ff6719 → #000000 Border
rgba(0, 0, 0, 0.10) → rgba(0,0,0,0.1) Display font
Cahuenga → OpenAI Sans Body size
19px → 16px colors 48 changed
~
bg-soft #f6f6f3 → #f1f1f1 ~
surface #ffffff → #fafafa ~
text #363737 → #000000 ~
text-strong #1a1a1a → #000000 ~
text-faint #a8a8a8 → #b4b4b4 ~
text-muted #878787 → #5d5d5d ~
brand #ff6719 → #000000 ~
brand-hover #e85412 → #1a1a1a ~
border rgba(0, 0, 0, 0.10) → rgba(0,0,0,0.1) ~
border-strong rgba(0, 0, 0, 0.20) → rgba(0,0,0,0.16) ~
border-soft rgba(0, 0, 0, 0.06) → rgba(0,0,0,0.08) ~
success #0d8050 → #10a37f ~
danger #dc2626 → #cc2525 ~
info #2563eb → #3a3a3a +
bg-section #f7f7f7 +
surface-card #ffffff +
surface-hover rgba(0,0,0,0.04) +
surface-press rgba(0,0,0,0.08) +
text-subtle #8e8e8e +
text-on-brand #ffffff +
text-on-dark #ededed +
brand-active #2c2c2c +
brand-on-dark #ffffff +
accent #10a37f +
accent-hover #0d8a6b +
accent-soft #d6f3e8 +
link #000000 +
link-hover #5d5d5d +
link-visited #000000 +
scrim rgba(0,0,0,0.5) +
shadow-card rgba(0,0,0,0.06) +
shadow-elev rgba(0,0,0,0.10) +
shadow-modal rgba(0,0,0,0.20) +
warning-soft #fdf3e7 +
danger-soft #fae5e5 −
bg-elev #fafaf7 −
bg-cream #fbf9f4 −
surface-warm #fafaf7 −
text-soft #666c70 −
text-link #363737 −
brand-deep #cc4a0e −
brand-tint rgba(255, 103, 25, 0.10) −
brand-tint-strong rgba(255, 103, 25, 0.18) −
border-warm rgba(0, 0, 0, 0.08) −
selection-bg rgba(255, 103, 25, 0.20) −
shadow-soft rgba(0, 0, 0, 0.06) −
shadow-medium rgba(0, 0, 0, 0.10) −
reading-rule rgba(0, 0, 0, 0.08) typography 5 changed
~
display {"family":"Cahuenga","size":56} → {"family":"OpenAI Sans","size":48} ~
h1 {"family":"Cahuenga","size":40} → {"family":"OpenAI Sans","size":40} ~
h2 {"family":"Cahuenga","size":32} → {"family":"OpenAI Sans","size":32} ~
body {"family":"Spectral","size":19} → {"family":"OpenAI Sans","size":16} ~
label {"family":"Monaco","size":13} → {"family":"OpenAI Sans Mono","size":12} radius 1 changed
~
button 6px → 8px spacing identical
No differences.