--- src/config.cc
+++ src/config.cc	2026-04-27 00:01:00.000000000 +0000
@@ -76,8 +76,9 @@
 }
 
 int VerifyColorCb(cfg_t *cfg, cfg_opt_t *opt, const char *c_value, void *v_result) {
-  static_assert(std::numeric_limits<long>::max() >= 0xFFFFFFFF,
-                "long should be 64 bits.");
+  // On 32-bit systems long is 32 bits and can't hold 0xFFFFFFFF as a positive value.
+  // Colors with high bit set will be stored as negative longs,
+  // but the bit pattern is preserved when cast back to uint32_t/SkColor.
 
   long *result = static_cast<long*>(v_result);
   string value{c_value};
@@ -89,14 +90,18 @@
     return -1;
   }
 
-  long color = std::stol(value, nullptr, 16);
+  // Use unsigned long for parsing to handle full 32-bit color range,
+  // then cast to long for storage in libconfuse.
+  unsigned long ucolor = std::stoul(value, nullptr, 16);
   if (value.size() == 8) {
     // No alpha value.
-    *result = 0xFF000000 | color;
+    ucolor = 0xFF000000UL | ucolor;
   } else {
     // Skia stores the alpha value at top, but traditional RGBA stores it at the bottom.
-    *result = (color << 24) | (color >> 8);
+    ucolor = (ucolor << 24) | (ucolor >> 8);
   }
+  // Cast to long - on 32-bit this may be negative, but bit pattern is preserved
+  *result = static_cast<long>(ucolor);
   return 0;
 }