Each product has an assigned "Type" which is identified by the background color. This type indicates the growth curve for that product. The more advanced the product, the faster its upgrade price will rise as its level increases.

Color Upgrade Cost Increase
Green 7 %
Yellow 8 %
Blue 9 %
Red 10 %
Violet 11 %
Product Product Type (Color)
Wood Green
Club Red
Arrows Blue
Bow Violet
Rawhide Green
Leather Yellow
Boots Red
Hilt Blue
Leather Armor Violet
Copper Ore Green
Copper Ingots Yellow
Copper Axe Red
Copper Blades Blue
Copper Knife Violet
Copper Dagger Violet
Tin Ore Green
Bronze Ingots Yellow
Bronze Spear Red
Bronze Shield Red
Bronze Blades Blue
Bronze Dagger Violet
Bronze Sword Violet
Sickle Violet
Coal Green
Iron Ore Green
Iron Ingots Yellow
Chisel Red
Iron Mace Red
Iron Rivets Blue
Shovel Red
Lump Hammer Red
Iron Helmet Red
Iron Plates Blue
Imp. Leather Armor Blue
Iron Blades Blue
Iron Sword Violet
Iron Armor Violet
Iron Claymore Violet
Paper Red
Gold Ore Green
Gold Ingots Yellow
Uncut Emerald Green
Gold Ring Red
Cut Emerald Yellow
Gold Necklace Violet
Emerald Ring Violet
Uncut Ruby Green
Paper Sheets Blue
Steel Yellow
Pickaxe Red
War Hammer Red
Steel Blades Blue
Cut Ruby Yellow
Map Violet
Ruby Ring Violet
Book Violet
Katana Red
Magnificent Bow Violet
Magnificent Hilt Blue
Magnificent Hammer Violet
Magnificent Dagger Violet
Magnificent Sword Violet
Rowboat Red
Uncut Sapphire Green
Magnificent Armor Violet
Mechanical Parts Blue
Spyglass Red
Magnificent Crossbow Violet
Sulfur Green
Cut Sapphire Yellow
Halberd Red
Microscope Violet
Compass Violet
Clockwork Blue
Saltpeter Green
Sapphire Ring Violet
Clock Red
Gunpowder Blue
Uncut Onyx Green
Weapon Parts Blue
Cut Onyx Yellow
Electro Magnet Red
Machine Parts Blue
Pistol Violet
Camera Violet
Onyx Ring Violet
Electrical Parts Blue
Musket Violet
Motor Unit Blue
Steam Engine Violet
Telephone Violet
Steam Boat Violet
Locomotive Violet