diff --git a/src/ui/FrameScript.cpp b/src/ui/FrameScript.cpp
index 558c517..d0e2802 100644
--- a/src/ui/FrameScript.cpp
+++ b/src/ui/FrameScript.cpp
@@ -444,7 +444,7 @@ void FrameScript_GetColor(lua_State* L, int32_t idx, CImVector& color) {
 
     float a = 1.0f;
     if (lua_isnumber(L, idx + 3)) {
-        a = lua_tonumber(L, idx + 2);
+        a = lua_tonumber(L, idx + 3);
         a = std::max(0.0f, std::min(a, 1.0f));
     }