diff --git a/auto-image-styles.css b/auto-image-styles.css
index 03445c9..5eafa93 100644
--- a/auto-image-styles.css
+++ b/auto-image-styles.css
@@ -83,8 +83,9 @@
   --wplace-pulse-mid: rgba(0, 255, 0, 0);
   --wplace-pulse-end: rgba(0, 255, 0, 0);
   
-  /* Slider colors */
+  /* Slider colors - defaults for classic compatibility */
   --wplace-slider-thumb-bg: white;
+  --wplace-slider-track-bg: linear-gradient(to right, var(--wplace-icon-primary) 0%, var(--wplace-icon-secondary) 100%);
 }
 
 /* Theme classes are now defined in separate files */
@@ -1777,7 +1778,7 @@
   width: 100%;
   -webkit-appearance: none;
   height: 8px;
-  background: linear-gradient(to right, var(--wplace-highlight) 0%, var(--wplace-highlight-secondary) 100%);
+  background: var(--wplace-slider-track-bg);
   border-radius: 4px;
   outline: none;
   cursor: pointer;
diff --git a/themes/classic.css b/themes/classic.css
index 3e1add8..50904f2 100644
--- a/themes/classic.css
+++ b/themes/classic.css
@@ -62,6 +62,7 @@
   
   /* Slider colors */
   --wplace-slider-thumb-bg: white;
+  --wplace-slider-track-bg: linear-gradient(to right, #4facfe 0%, #00f2fe 100%);
 }
 
 /* Classic theme container styling */