Support blue yellow colorblind theme (#35910)

This icon is from GitHub:

<img width="350" height="350" alt="image"
src="https://github.com/user-attachments/assets/c3f31901-5359-4b7f-ae68-eddcec63df53"
/>

---------

Signed-off-by: 鲁汀 <131967983+lutinglt@users.noreply.github.com>
Co-authored-by: lutinglt <lutinglt@users.noreply.github.com>

public/assets/img/svg/gitea-colorblind-blueyellow.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 40 40" class="svg gitea-colorblind-blueyellow" width="16" height="16" aria-hidden="true"><g clip-path="url(#gitea-colorblind-blueyellow__a)"><rect width="40" height="40" fill="#0000" rx="20"/><path fill="#1d69e0" d="M34.284 34.284c7.81-7.81 7.81-20.474 0-28.284L6 34.284c7.81 7.81 20.474 7.81 28.284 0"/><path fill="#fa4549" d="M34.283 34.284c7.81-7.81 7.81-20.474 0-28.284L20.14 20.142z"/><circle cx="20" cy="20" r="18" fill="#0000" stroke="#aaa" stroke-width="4"/></g><defs><clipPath id="gitea-colorblind-blueyellow__a"><rect width="40" height="40" fill="#0000" rx="20"/></clipPath></defs></svg>

services/webtheme/webtheme.go

@@ -39,6 +39,9 @@ func (info *ThemeMetaInfo) GetDescription() string {
 	if info.ColorblindType == "red-green" {
 		return "Red-green colorblind friendly"
 	}
+	if info.ColorblindType == "blue-yellow" {
+		return "Blue-yellow colorblind friendly"
+	}
 	return ""
 }
 
@@ -46,6 +49,9 @@ func (info *ThemeMetaInfo) GetExtraIconName() string {
 	if info.ColorblindType == "red-green" {
 		return "gitea-colorblind-redgreen"
 	}
+	if info.ColorblindType == "blue-yellow" {
+		return "gitea-colorblind-blueyellow"
+	}
 	return ""
 }
 

web_src/css/themes/theme-gitea-auto-tritanopia.css

@@ -0,0 +1,8 @@
+@import "./theme-gitea-light-tritanopia.css" (prefers-color-scheme: light);
+@import "./theme-gitea-dark-tritanopia.css" (prefers-color-scheme: dark);
+
+gitea-theme-meta-info {
+  --theme-display-name: "Auto";
+  --theme-colorblind-type: "blue-yellow";
+  --theme-color-scheme: "auto";
+}

web_src/css/themes/theme-gitea-dark-tritanopia.css

@@ -0,0 +1,15 @@
+@import "./theme-gitea-dark-protanopia-deuteranopia.css";
+
+gitea-theme-meta-info {
+  --theme-display-name: "Dark";
+  --theme-colorblind-type: "blue-yellow";
+  --theme-color-scheme: "dark";
+}
+
+/* blue/yellow colorblind-friendly colors */
+/* from GitHub: blue yellow blindness is based on red green blindness, and --diffBlob-deletion-* restored to the normal theme color */
+:root {
+  --color-diff-removed-linenum-bg: #482121;
+  --color-diff-removed-row-bg: #301e1e;
+  --color-diff-removed-word-bg: #6f3333;
+}

web_src/css/themes/theme-gitea-light-tritanopia.css

@@ -0,0 +1,15 @@
+@import "./theme-gitea-light-protanopia-deuteranopia.css";
+
+gitea-theme-meta-info {
+  --theme-display-name: "Light";
+  --theme-colorblind-type: "blue-yellow";
+  --theme-color-scheme: "light";
+}
+
+/* blue/yellow colorblind-friendly colors */
+/* from GitHub: blue yellow blindness is based on red green blindness, and --diffBlob-deletion-* restored to the normal theme color */
+:root {
+  --color-diff-removed-linenum-bg: #ffcecb;
+  --color-diff-removed-row-bg: #ffeef0;
+  --color-diff-removed-word-bg: #fdb8c0;
+}

web_src/svg/gitea-colorblind-blueyellow.svg

@@ -0,0 +1,13 @@
+<svg width="40" height="40" viewBox="0 0 40 40" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <g clip-path="url(#clip0)">
+    <rect width="40" height="40" rx="20" fill="#0000"/>
+    <path d="M34.2843 34.2842C42.0948 26.4737 42.0948 13.8104 34.2843 5.9999L6 34.2842C13.8105 42.0947 26.4738 42.0947 34.2843 34.2842Z" fill="#1D69E0"/>
+    <path d="M34.2828 34.2842C42.0932 26.4737 42.0932 13.8104 34.2828 5.99995L20.1406 20.1421L34.2828 34.2842Z" fill="#fa4549"/>
+    <circle cx="20" cy="20" r="18" fill="#0000" stroke="#aaa" stroke-width="4"/>
+  </g>
+  <defs>
+    <clipPath id="clip0">
+      <rect width="40" height="40" rx="20" fill="#0000"/>
+    </clipPath>
+  </defs>
+</svg>