It’s true that pharmacists would often use dark colored bottles, but drugs that came pre-bottled from manufacturers were very often in clear bottles, many with the name of the medication or manufacturer molded into the glass.
Laudanum was frequently found in clear glass bottles, often thin and tall. I can attest from experience that similar bottles are very difficult to find, and your best bet is to look on eBay or local antique stores (if you go to a local store, bring a picture with you so you can show them what you’re looking for, you’d be surprised what they often have not on display due to lack of space).
Forty, I believe that the photo that litl rooster posted is of an empty bottle—the color you’re seeing is likely the remnants coating the glass. Laudanum is still sold today (with a prescription), and you can find photos online which match the descriptions from the period—dark, reddish brown in color, fairly opaque. In terms of odor, it was typically flavored with cinnamon or saffron to mask the extreme bitterness of the opium. The base was frequently ethyl alcohol, which made it quite a powerful combination (and extremely dangerous).