diff --git a/src/graphics.c b/src/graphics.c
index fe1eef5..3b656fe 100644
--- a/src/graphics.c
+++ b/src/graphics.c
@@ -39,7 +39,7 @@ static int getColorFromArgs(lua_State *L, int *rgb, const int *def) {
     g = luaL_checkint(L, 2);
     b = luaL_checkint(L, 3);
   }
-  int idx = palette_colorIdx(r, g, b);
+  int idx = palette_colorToIdx(r, g, b);
   if (idx < 0) {
     luaL_error(L, "color palette exhausted: use fewer unique colors");
   }
diff --git a/src/image.c b/src/image.c
index 46fa2a4..0d3b35b 100644
--- a/src/image.c
+++ b/src/image.c
@@ -61,7 +61,7 @@ const char *image_init(image_t *self, const char *filename) {
     int g = p[1];
     int b = p[2];
     int a = p[3];
-    int idx = palette_colorIdx(r, g, b);
+    int idx = palette_colorToIdx(r, g, b);
     if (idx < 0) {
       errmsg = "color palette exhausted: use fewer unique colors";
       goto fail;
diff --git a/src/palette.c b/src/palette.c
index 8c29051..989bfb4 100644
--- a/src/palette.c
+++ b/src/palette.c
@@ -40,7 +40,7 @@ static unsigned hash(const void *data, int size) {
 }
 
 
-int palette_colorIdx(int r, int g, int b) {
+int palette_colorToIdx(int r, int g, int b) {
   palette_init();
 
   /* Make 18bit rgb color (6bits per-channel) from 8bit channels  */
diff --git a/src/palette.h b/src/palette.h
index 5fc7cbc..dfeac64 100644
--- a/src/palette.h
+++ b/src/palette.h
@@ -3,6 +3,6 @@
 
 void palette_init(void);
 void palette_reset(void);
-int palette_colorIdx(int r, int g, int b);
+int palette_colorToIdx(int r, int g, int b);
 
 #endif