i18n: french color label

Translate the remaining English "Color" label in the edit panel's
colour picker to "Couleur", matching the already-French controls
("Tourner", "Créer"/"Modifier").

src/components/UI/Panel/ColorInput/index.jsx

@@ -20,7 +20,7 @@ export const ColorInput = () => {
 
   return (
     <div className="SliderInputContainer">
-      <label className="SliderLabel">Color</label>
+      <label className="SliderLabel">Couleur</label>
       <HexColorPicker color="#000000" onChange={debouncesetColor} />
     </div>
   );