Choosing the right pebbles for your aquarium has a lot to do with the health of your fish and not so much to do with the color of the pebbles.
You've heard of the expression "you get what you pay for"? This couldn't be closer to the truth when it comes to aquarium pebbles. People often look to the low-end of pricing when purchasing pebbles for their fish tanks and in turn ignore the health of their fish.
Fish are extremely sensitive to the chemical balance of the water they live in. Think of it this way, imagine standing in a room with clean air and then suddenly brining in a handful of smokers - you get the idea, right?
Fish react the same way to a change in their environment and the toxicity or non-toxicity of aquarium pebbles can have an extreme impact on their health. To the point that your fish may even die if you are not careful.
When purchasing aquarium pebbles make sure to check if they are 100% non-toxic. Cheaper pebbles may in fact be cheap for the very reason that they are not natural pebbles or they have some kind of coating (to make cleaning easier) that will change the chemical balance of the water in your aquarium.
This doesn't mean that all coated pebbles are toxic. Coated pebbles are meant to perform several functions, which include making cleaning easier and even providing a healthy home for beneficial bacteria to colonize. Yes, believe it or not, but bacteria can be beneficial to an aquarium.
There are various aquarium pebbles, and even aquarium sand, on the market today. You can find coated pebbles, natural pebbles, and sand packaged in about 5lb bags and prices will vary depending on the quality.
Remember, when choosing pebbles for your aquarium that you should not always use price as your guide.