diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b72fd19b6..acfeafd754 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ Docs: https://docs.openclaw.ai
 - macOS Voice Wake: fix a crash in trigger trimming for CJK/Unicode transcripts by matching and slicing on original-string ranges instead of transformed-string indices. (#11052) Thanks @Flash-LHR.
 - Heartbeat: prevent scheduler silent-death races during runner reloads, preserve retry cooldown backoff under wake bursts, and prioritize user/action wake causes over interval/retry reasons when coalescing. (#15108) Thanks @joeykrug.
 - Exec/Allowlist: allow multiline heredoc bodies (`<<`, `<<-`) while keeping multiline non-heredoc shell commands blocked, so exec approval parsing permits heredoc input safely without allowing general newline command chaining. (#13811) Thanks @mcaxtr.
+- Docs/Mermaid: remove hardcoded Mermaid init theme blocks from four docs diagrams so dark mode inherits readable theme defaults. (#15157) Thanks @heytulsiprasad.
 
 ## 2026.2.12
 
diff --git a/docs/concepts/architecture.md b/docs/concepts/architecture.md
index 42017ab5e9..24e1fb69f7 100644
--- a/docs/concepts/architecture.md
+++ b/docs/concepts/architecture.md
@@ -56,22 +56,6 @@ Protocol details:
 ## Connection lifecycle (single client)
 
 ```mermaid
-%%{init: {
-  'theme': 'base',
-  'themeVariables': {
-    'primaryColor': '#ffffff',
-    'primaryTextColor': '#000000',
-    'primaryBorderColor': '#000000',
-    'lineColor': '#000000',
-    'secondaryColor': '#f9f9fb',
-    'tertiaryColor': '#ffffff',
-    'clusterBkg': '#f9f9fb',
-    'clusterBorder': '#000000',
-    'nodeBorder': '#000000',
-    'mainBkg': '#ffffff',
-    'edgeLabelBackground': '#ffffff'
-  }
-}}%%
 sequenceDiagram
     participant Client
     participant Gateway
diff --git a/docs/gateway/remote-gateway-readme.md b/docs/gateway/remote-gateway-readme.md
index 8fa9cd1f09..27fbfb6d2a 100644
--- a/docs/gateway/remote-gateway-readme.md
+++ b/docs/gateway/remote-gateway-readme.md
@@ -11,22 +11,6 @@ OpenClaw.app uses SSH tunneling to connect to a remote gateway. This guide shows
 ## Overview
 
 ```mermaid
-%%{init: {
-  'theme': 'base',
-  'themeVariables': {
-    'primaryColor': '#ffffff',
-    'primaryTextColor': '#000000',
-    'primaryBorderColor': '#000000',
-    'lineColor': '#000000',
-    'secondaryColor': '#f9f9fb',
-    'tertiaryColor': '#ffffff',
-    'clusterBkg': '#f9f9fb',
-    'clusterBorder': '#000000',
-    'nodeBorder': '#000000',
-    'mainBkg': '#ffffff',
-    'edgeLabelBackground': '#ffffff'
-  }
-}}%%
 flowchart TB
     subgraph Client["Client Machine"]
         direction TB
diff --git a/docs/gateway/security/index.md b/docs/gateway/security/index.md
index 9ae56fb80e..14a3f17b00 100644
--- a/docs/gateway/security/index.md
+++ b/docs/gateway/security/index.md
@@ -801,22 +801,6 @@ Commit the updated `.secrets.baseline` once it reflects the intended state.
 ## The Trust Hierarchy
 
 ```mermaid
-%%{init: {
-  'theme': 'base',
-  'themeVariables': {
-    'primaryColor': '#ffffff',
-    'primaryTextColor': '#000000',
-    'primaryBorderColor': '#000000',
-    'lineColor': '#000000',
-    'secondaryColor': '#f9f9fb',
-    'tertiaryColor': '#ffffff',
-    'clusterBkg': '#f9f9fb',
-    'clusterBorder': '#000000',
-    'nodeBorder': '#000000',
-    'mainBkg': '#ffffff',
-    'edgeLabelBackground': '#ffffff'
-  }
-}}%%
 flowchart TB
     A["Owner (Peter)"] -- Full trust --> B["AI (Clawd)"]
     B -- Trust but verify --> C["Friends in allowlist"]
diff --git a/docs/start/openclaw.md b/docs/start/openclaw.md
index 874a8d85c8..fec776bb8f 100644
--- a/docs/start/openclaw.md
+++ b/docs/start/openclaw.md
@@ -34,22 +34,6 @@ Start conservative:
 You want this:
 
 ```mermaid
-%%{init: {
-  'theme': 'base',
-  'themeVariables': {
-    'primaryColor': '#ffffff',
-    'primaryTextColor': '#000000',
-    'primaryBorderColor': '#000000',
-    'lineColor': '#000000',
-    'secondaryColor': '#f9f9fb',
-    'tertiaryColor': '#ffffff',
-    'clusterBkg': '#f9f9fb',
-    'clusterBorder': '#000000',
-    'nodeBorder': '#000000',
-    'mainBkg': '#ffffff',
-    'edgeLabelBackground': '#ffffff'
-  }
-}}%%
 flowchart TB
     A["<b>Your Phone (personal)<br></b><br>Your WhatsApp<br>+1-555-YOU"] -- message --> B["<b>Second Phone (assistant)<br></b><br>Assistant WA<br>+1-555-ASSIST"]
     B -- linked via QR --> C["<b>Your Mac (openclaw)<br></b><br>Pi agent"]