When I need to make really colorful, sturdy bubbles, I add glycerine to the mix. Glycerine sold in rose water or other solutions is pretty much worthless. A much more practical and less expensive additive is white Karo Syrup which is available at the grocery store. Water, a key ingredient, varies widely in its quality. One bubble solution manufacturer I know ships huge containers of water from the USA to its mixing plant in China where water quality doesn't meet the necessary standards.
Soft water is good for bubbles.
Hard water, well water, and any water containing high levels of iron is bad for bubbles. To get the best mixture, try using distilled water which is available at the grocery store.