diff --git a/include/conf.h b/include/conf.h
index c750632..9d02f55 100644
--- a/include/conf.h
+++ b/include/conf.h
@@ -2,13 +2,26 @@
 /* Copyright (C) 2021 KikooDX */
 #pragma once
 
-static const int game_window_width = 396;
-static const int game_window_height = 224;
-static const int picker_window_width = 256;
-static const int picker_window_height = 256;
-static const int draw_offset_x = -2;
-static const int draw_offset_y = -8;
-static const int tile_width = 16;
-static const int tile_height = 16;
+#include <raylib.h> /* for the color struct */
+
+#define TILE_WIDTH 16 /* in pixels */
+#define TILE_HEIGHT 16
+#define TILESET_WIDTH 16 /* in tiles */
+#define TILESET_HEIGHT 16
+#define TILESET_MIN_WIDTH_PX (TILE_WIDTH * TILESET_WIDTH)
+#define TILESET_MIN_HEIGHT_PX (TILE_HEIGHT * TILESET_HEIGHT)
+
 static const int editor_target_fps = 60;
 static const int picker_target_fps = 30;
+static const Color unselected_tile_color = {80, 80, 80, 255};
+
+static const int editor_window_width = 396;
+static const int editor_window_height = 224;
+static const int draw_offset_x = -2;
+static const int draw_offset_y = -8;
+
+#define PICKER_PADDING 4
+static const int picker_window_width =
+    (TILE_WIDTH + PICKER_PADDING) * TILESET_WIDTH + PICKER_PADDING;
+static const int picker_window_height =
+    (TILE_HEIGHT + PICKER_PADDING) * TILESET_HEIGHT + PICKER_PADDING;
diff --git a/include/tile_picker/draw.h b/include/tile_picker/draw.h
index 3041a68..968d4d5 100644
--- a/include/tile_picker/draw.h
+++ b/include/tile_picker/draw.h
@@ -4,4 +4,4 @@
 
 #include <raylib.h>
 
-void tileset_draw(Texture2D tileset);
+void tileset_draw(Texture2D tileset, int selected_tile);
diff --git a/src/editing_area/draw.c b/src/editing_area/draw.c
index 1c9f5bd..415f001 100644
--- a/src/editing_area/draw.c
+++ b/src/editing_area/draw.c
@@ -14,13 +14,13 @@ void level_draw(struct Level level, Texture2D tileset)
 		for (y = 0; y < level.height; y += 1) {
 			const int tile =
 			    level.data[x + y * level.width];
-			Rectangle tile_rect = {
-			    (int)(tile % tileset.width) * tile_width,
-			    (int)(tile / tileset.width) * tile_width,
-			    tile_width, tile_height};
-			Vector2 tile_pos = {
-			    x * tile_width + draw_offset_x,
-			    y * tile_height + draw_offset_y};
+			const Rectangle tile_rect = {
+			    (int)(tile % TILESET_WIDTH) * TILE_WIDTH,
+			    (int)(tile / TILESET_HEIGHT) * TILE_WIDTH,
+			    TILE_WIDTH, TILE_HEIGHT};
+			const Vector2 tile_pos = {
+			    x * TILE_WIDTH + draw_offset_x,
+			    y * TILE_HEIGHT + draw_offset_y};
 			if (tile)
 				DrawTextureRec(tileset, tile_rect,
 				               tile_pos, WHITE);
diff --git a/src/editing_area/main.c b/src/editing_area/main.c
index a43923c..6f8858f 100644
--- a/src/editing_area/main.c
+++ b/src/editing_area/main.c
@@ -7,6 +7,7 @@
 #include "shared_data.h"
 #include <raylib.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <sys/wait.h>
 
@@ -17,14 +18,15 @@ int editing_area_main(int argc, char **argv,
 	level.data = NULL;
 
 	/* initialize raylib */
-	InitWindow(game_window_width, game_window_height,
+	InitWindow(editor_window_width, editor_window_height,
 	           "SLE main window");
 	SetTargetFPS(editor_target_fps);
 	/* load textures */
 	const Texture2D tileset = LoadTexture(argv[1]);
 
-	/* only proceed if tileset is well loaded */
-	if (tileset.width > 0) {
+	/* only proceed if tileset is large enough */
+	if (tileset.width >= TILESET_MIN_WIDTH_PX &&
+	    tileset.height >= TILESET_MIN_HEIGHT_PX) {
 		/* load level */
 		level_read(&level, argv[2]);
 
@@ -40,7 +42,12 @@ int editing_area_main(int argc, char **argv,
 
 		/* save level */
 		level_write(level, argv[2]);
-	}
+	} else
+		fprintf(stderr,
+		        "ERROR: tileset size is invalid, expected at "
+		        "least [%d ; %d], got [%d ; %d]\n",
+		        TILESET_MIN_WIDTH_PX, TILESET_MIN_HEIGHT_PX,
+		        tileset.width, tileset.height);
 
 	/* deinit */
 	level_free(&level);
diff --git a/src/main.c b/src/main.c
index 0877886..34767ce 100644
--- a/src/main.c
+++ b/src/main.c
@@ -23,7 +23,7 @@ int main(int argc, char **argv)
 	    (struct SharedData *)create_shared_memory(
 		sizeof(struct SharedData));
 	shared_data->end_child = false;
-	shared_data->selected_tile = 1;
+	shared_data->selected_tile = 69;
 	pid_t child_process;
 
 	/* set log level */
diff --git a/src/tile_picker/draw.c b/src/tile_picker/draw.c
index 63edc8e..f027377 100644
--- a/src/tile_picker/draw.c
+++ b/src/tile_picker/draw.c
@@ -2,9 +2,31 @@
 /* Copyright (C) 2021 KikooDX */
 
 #include "tile_picker/draw.h"
+#include "conf.h"
 #include <raylib.h>
 
-void tileset_draw(Texture2D tileset)
+void tileset_draw(Texture2D tileset, int selected_tile)
 {
-	DrawTexture(tileset, 0, 0, WHITE);
+	int x;
+	int y;
+	/* draw tiles */
+	for (x = 0; x < TILESET_WIDTH; x += 1) {
+		for (y = 0; y < TILESET_HEIGHT; y += 1) {
+			const Rectangle tile_rect = {
+			    x * TILE_WIDTH, y * TILE_HEIGHT, TILE_WIDTH,
+			    TILE_HEIGHT};
+			const Vector2 tile_pos = {
+			    x * (TILE_WIDTH + PICKER_PADDING) +
+				PICKER_PADDING,
+			    y * (TILE_HEIGHT + PICKER_PADDING) +
+				PICKER_PADDING};
+			/* apply tint if tile isn't selected */
+			Color tint = unselected_tile_color;
+			if (x + y * TILESET_WIDTH == selected_tile)
+				tint = WHITE;
+			/* draw the tile */
+			DrawTextureRec(tileset, tile_rect, tile_pos,
+			               tint);
+		}
+	}
 }
diff --git a/src/tile_picker/main.c b/src/tile_picker/main.c
index 3533523..0990735 100644
--- a/src/tile_picker/main.c
+++ b/src/tile_picker/main.c
@@ -24,7 +24,8 @@ int tile_picker_main(int argc, char **argv,
 			BeginDrawing();
 
 			ClearBackground(BLACK);
-			tileset_draw(tileset);
+			tileset_draw(tileset,
+			             shared_data->selected_tile);
 
 			EndDrawing();
 		}