diff --git a/sc2/src/uqm/planets/generate/genrain-modern.cpp b/sc2/src/uqm/planets/generate/genrain-modern.cpp
index 0aa2f0ecb..1976d9e9d 100644
--- a/sc2/src/uqm/planets/generate/genrain-modern.cpp
+++ b/sc2/src/uqm/planets/generate/genrain-modern.cpp
@@ -24,6 +24,7 @@
 #include "libs/mathlib.h"
 
 #include <iostream>
+#include <algorithm>
 
 namespace
 {
@@ -37,6 +38,8 @@ namespace
 			bool generatePlanets( SolarSystem *solarSys ) override;
 			bool generateOrbital( SolarSystem *solarSys,
 					PLANET_DESC *world ) override;
+
+			static int getRainbowIndex();
 	};
 
 	auto init= []
@@ -77,22 +80,11 @@ GenerateRainbowWorld::generateOrbital( SolarSystem *const solarSys, PLANET_DESC
 {
 	if (matchWorld (solarSys, world, 0, MATCH_PLANET))
 	{
-		BYTE which_rainbow;
-		UWORD rainbow_mask;
-		STAR_DESC *SDPtr;
+		const int which_rainbow= getRainbowIndex();
+		UWORD rainbow_mask = MAKE_WORD (
+			GET_GAME_STATE (RAINBOW_WORLD0),
+			GET_GAME_STATE (RAINBOW_WORLD1));
 
-		rainbow_mask = MAKE_WORD (
-				GET_GAME_STATE (RAINBOW_WORLD0),
-				GET_GAME_STATE (RAINBOW_WORLD1));
-
-		which_rainbow = 0;
-		SDPtr = &star_array[0];
-		while (SDPtr != CurStarDescPtr)
-		{
-			if (SDPtr->supplement and SDPtr->supplement == "Rainbow"s)
-				++which_rainbow;
-			++SDPtr;
-		}
 		std::cerr << "I think I'm at Rainbow world #" << (int) which_rainbow << std::endl;
 		rainbow_mask |= 1 << which_rainbow;
 		SET_GAME_STATE (RAINBOW_WORLD0, LOBYTE (rainbow_mask));
@@ -103,3 +95,14 @@ GenerateRainbowWorld::generateOrbital( SolarSystem *const solarSys, PLANET_DESC
 	return true;
 }
 
+
+int
+GenerateRainbowWorld::getRainbowIndex()
+{
+	return std::count_if( star_array, CurStarDescPtr,
+		[]( const auto &star )
+		{
+			return star.supplement and star.supplement == "Rainbow"s;
+		}
+	);
+}