The short answer
Rum cocktails range from the simple Daiquiri to the multi-layered Mai Tai. Choose the bottle to match the recipe. White, golden, and dark tell you little about how a rum actually tastes. What matters more is the style and strength a recipe calls for.

Fresh and Simple: Daiquiri and Mojito
A Daiquiri has three ingredients: rum, lime, and sugar. That's exactly why you can taste every ratio instantly. Too much sugar makes it cloying; too little makes the drink harsh and sour. The Mojito adds mint, soda, and ice. The core stays the same.
For both drinks, the rum you choose matters. A heavily cask-driven or noticeably sweetened substitute changes the result significantly. The two simplest variables are in your own hands: freshly squeezed citrus juice and measured sweetness.
The Daiquiri is the most honest test for a bottle. Three ingredients, nothing to hide behind. If a rum tastes good in it, it's fit for almost any other drink too. Fresh lime is a must here. Bottled juice tastes different and makes the whole exercise pointless.
Measure your ingredients, even if that seems like extra effort. Mixed by feel, the same drink tastes different on two different evenings. With a jigger, though, you know exactly what to adjust next time.
Bitter and Fruity: Jungle Bird
The Jungle Bird brings rum together with pineapple, lime, and a red bitter aperitif. The bitterness belongs to the drink. It shouldn't be masked by extra syrup.
That makes it a good direction for anyone who finds pure fruit drinks too sweet. That said, it doesn't become a pure spirits cocktail. The pineapple keeps it approachable, while the bitter aperitif takes the edge off the sweetness.
One note on the bitter aperitif: alongside bitterness, it also brings sweetness and colour. Leave it out and you won't get a Jungle Bird without bitterness—you'll get a different drink entirely.

Why Some Recipes Call for Multiple Rums
In a Mai Tai or a Zombie, several rums sit side by side. That's not a coincidence, and it's not an invitation to empty out leftovers. Each rum has a job to do there. One brings fruit, one brings depth from the cask, one brings strength.
So stick to the styles called for. Swap out at most one component at a time, or you won't know afterwards where the change came from. Overproof rum is a special case here. Its higher alcohol strength can't simply be swapped in at the same quantity.
Replace two rums with one, and you don't get a simplified drink—you get an incomplete one. If you're missing an ingredient, a different recipe is the better choice. Half a Mai Tai doesn't taste like anything in particular.
Choosing for Your First Home Bar
Start with the ingredients for two drinks you'll actually want to drink. A white rum, fresh limes, and sugar are enough to begin with. That already opens up several classics, and along the way you'll learn your own taste.
Tiki recipes call for special syrups and liqueurs on top of that. Check these ingredients before you shop. Orgeat, for instance, is an almond syrup and not just another name for simple syrup. Mix that up and you'll buy the wrong bottle and wonder why the drink tastes off.
One rule saves money and shelf space: buy for the drinks you want to make, not for the collection. Two bottles that regularly run empty are worth more than eight, six of which just evaporate on the shelf.
With ice, a little effort goes a long way. Large, hard cubes melt slowly and barely dilute the drink. Small, soft cubes melt fast. After five minutes you're left with a watery cocktail, even though you measured everything correctly.