Many swear by the warm white; I (and DW) dislike the dingy yellow color, especially in an older RV; makes everthing look older and dirty. 4500-5500K is a very bright, pure white, which is what worked best for us throughout the RV. "Cool" white is typically over 5500K, and has a blue tint (the higher the number, the bluer it looks). I replaced every single bulb in my RV (more than 25) for less than $130, most from Amazon, some from eBay. Super happy with the color, light output, and (lack of) current draw. No failures in more than 18 months, using both onboard batteries, generator, or hookups. I will never go back to incandescent, and I will never pay inflated prices from an RV place. $8-$20 for a single LED replacement? No way; no reason.
Here's the best argument I can make for purchasing cheap LEDs online: There are a million different LED replacements out there; different bases (T10, BA9, BA15, Wedge, Festoon...), different layouts (flat panel, COB, cylindrical...), different LEDs (1210, 3528, 5050, 5630...), different color temps (anything from 2700K to 6500K and above; warm, pure, daylight, cool, bright...), different lumen outputs... At $8-20 each, you better know exactly what YOU want and what YOU like. Do you? I certainly didn't, and that was even after doing a ton of online reseach. With cheap LEDs, you can purchase 1-2 of each of several different types and try them out. If you don't like them, you haven't lost much (or they can often be used in a different location/appliction). If you do like them, then order more.
Here's my conversion details, with lots of in-depth info. Although it's now a year and a half old, it has alot of info that is quite useful to anyone who is just starting down the LED road. You will learn alot about the different types, temps, bases, sizes, layout, etc., in order to make the decisions that YOU will be happy with. No longer is a light bulb a light bulb; there are numerous variations, and no one else can make those descisions for you, because no one else knows exactly what you like.
Good luck:D