diff --git a/src/MinedMap.cpp b/src/MinedMap.cpp
index bb2c46e..404927a 100644
--- a/src/MinedMap.cpp
+++ b/src/MinedMap.cpp
@@ -77,7 +77,8 @@ static void addChunk(Resource::Color image[DIM*DIM], uint8_t lightmap[2*DIM*DIM]
 			const World::Chunk::Height &height = layer.v[x][z];
 			World::Block block = chunk.getBlock(x, height, z);
 
-			image[i] = block.getColor(biomemaps[1][1].get()[i]);
+			if (block.isVisible())
+				image[i] = block.getColor(biomemaps[1][1].get()[i]);
 			lightmap[2*i+1] = (1 - block.blockLight/15.f)*192;
 		}
 	}
@@ -259,7 +260,6 @@ static void makeMap(const std::string &regiondir, const std::string &outputdir,
 		}
 
 		std::unique_ptr<Resource::Color[]> image(new Resource::Color[DIM*DIM]);
-		std::memset(image.get(), 0, 4*DIM*DIM);
 
 		std::unique_ptr<uint8_t[]> lightmap(new uint8_t[2*DIM*DIM]);
 		std::memset(lightmap.get(), 0, 2*DIM*DIM);
diff --git a/src/Resource/Biome.cpp b/src/Resource/Biome.cpp
index 2d2dbb5..440b1d4 100644
--- a/src/Resource/Biome.cpp
+++ b/src/Resource/Biome.cpp
@@ -34,59 +34,35 @@
 namespace MinedMap {
 namespace Resource {
 
-static Biome::FloatColor operator+(const Biome::FloatColor &a, const Biome::FloatColor &b){
-	return Biome::FloatColor {
-		a.r+b.r,
-		a.g+b.g,
-		a.b+b.b,
-	};
-}
-
-static Biome::FloatColor & operator*=(Biome::FloatColor &a, const Biome::FloatColor &b) {
-	a.r *= b.r;
-	a.g *= b.g;
-	a.b *= b.b;
-
-	return a;
-}
-
-static Biome::FloatColor operator*(float s, const Biome::FloatColor &c) {
-	return Biome::FloatColor {
-		s*c.r,
-		s*c.g,
-		s*c.b,
-	};
-}
-
-static Biome::FloatColor colorFromParams(float temp, float rain, bool grass) {
-	const Biome::FloatColor grassColors[3] = {
+static FloatColor colorFromParams(float temp, float rain, bool grass) {
+	const FloatColor grassColors[3] = {
 		{0.502f, 0.706f, 0.592f}, // lower right
 		{0.247f, 0.012f, -0.259f}, // lower left - lower right
 		{-0.471f, 0.086f, -0.133f}, // upper left - lower left
 	};
-	const Biome::FloatColor foliageColors[3] = {
+	const FloatColor foliageColors[3] = {
 		{0.376f, 0.631f, 0.482f}, // lower right
 		{0.306f, 0.012f, -0.317f}, // lower left - lower right
 		{-0.580f, 0.106f, -0.165f}, // upper left - lower left
 	};
 
-	const Biome::FloatColor *colors = grass ? grassColors : foliageColors;
+	const FloatColor *colors = grass ? grassColors : foliageColors;
 
 	return colors[0] + temp*colors[1] + rain*colors[2];
 }
 
 
-Biome::FloatColor Biome::getGrassColor(float temp, float rain) const {
+FloatColor Biome::getGrassColor(float temp, float rain) const {
 	return colorFromParams(temp, rain, true);
 }
 
-Biome::FloatColor Biome::getFoliageColor(float temp, float rain) const {
+FloatColor Biome::getFoliageColor(float temp, float rain) const {
 	return colorFromParams(temp, rain, false);
 }
 
 
-Color Biome::getBlockColor(const BlockType *type, unsigned height) const {
-	Biome::FloatColor c = {
+FloatColor Biome::getBlockColor(const BlockType *type, unsigned height) const {
+	FloatColor c = {
 		float(type->color.r),
 		float(type->color.g),
 		float(type->color.b),
@@ -108,12 +84,11 @@ Color Biome::getBlockColor(const BlockType *type, unsigned height) const {
 
 	float h = 0.5f + height * 0.005f;
 
-	return Color {
-		uint8_t(clamp(c.r * h, 0, 255)),
-		uint8_t(clamp(c.g * h, 0, 255)),
-		uint8_t(clamp(c.b * h, 0, 255)),
-		0xff,
-	};
+	c.r = clamp(c.r * h, 0, 255);
+	c.g = clamp(c.g * h, 0, 255);
+	c.b = clamp(c.b * h, 0, 255);
+
+	return c;
 }
 
 
diff --git a/src/Resource/Biome.hpp b/src/Resource/Biome.hpp
index b63406a..e094f17 100644
--- a/src/Resource/Biome.hpp
+++ b/src/Resource/Biome.hpp
@@ -35,11 +35,6 @@ namespace Resource {
 class BlockType;
 
 class Biome {
-public:
-	struct FloatColor {
-		float r, g, b;
-	};
-
 private:
 	float temp, rain;
 	FloatColor water;
@@ -54,7 +49,7 @@ public:
 	Biome(float temp0, float rain0, FloatColor water0 = {0.247f, 0.463f, 0.894f})
 	: temp(temp0), rain(rain0), water(water0) {}
 
-	Color getBlockColor(const BlockType *type, unsigned height) const;
+	FloatColor getBlockColor(const BlockType *type, unsigned height) const;
 };
 
 extern const Biome *const BIOME_DEFAULT;
diff --git a/src/Resource/Color.hpp b/src/Resource/Color.hpp
index 2eddc0b..bad2df6 100644
--- a/src/Resource/Color.hpp
+++ b/src/Resource/Color.hpp
@@ -32,8 +32,39 @@
 namespace MinedMap {
 namespace Resource {
 
+struct FloatColor {
+	float r, g, b;
+};
+
+static inline FloatColor operator+(const FloatColor &a, const FloatColor &b){
+	return FloatColor {
+		a.r+b.r,
+		a.g+b.g,
+		a.b+b.b,
+	};
+}
+
+static inline FloatColor & operator*=(FloatColor &a, const FloatColor &b) {
+	a.r *= b.r;
+	a.g *= b.g;
+	a.b *= b.b;
+
+	return a;
+}
+
+static inline FloatColor operator*(float s, const FloatColor &c) {
+	return FloatColor {
+		s*c.r,
+		s*c.g,
+		s*c.b,
+	};
+}
+
 struct Color {
 	uint8_t r, g, b, a;
+
+	Color() : r(0), g(0), b(0), a(0) {}
+	Color(FloatColor c) : r(c.r), g(c.g), b(c.b), a(0xff) {}
 };
 
 }
diff --git a/src/World/Block.hpp b/src/World/Block.hpp
index 3143d15..30ed186 100644
--- a/src/World/Block.hpp
+++ b/src/World/Block.hpp
@@ -39,10 +39,13 @@ struct Block {
 	unsigned depth;
 	uint8_t blockLight;
 
+	bool isVisible() const {
+		return type && (type->flags & BLOCK_OPAQUE);
+	}
 
-	Resource::Color getColor(uint8_t biome) const {
-		if (!type || !(type->flags & BLOCK_OPAQUE))
-			return Resource::Color {};
+	Resource::FloatColor getColor(uint8_t biome) const {
+		if (!isVisible())
+			return Resource::FloatColor {};
 
 		return (Resource::BIOMES[biome] ?: Resource::BIOME_DEFAULT)->getBlockColor(type, depth);
 	}