A "Hand Open Rainbow Umbrella" typically refers to an umbrella that opens manually and features a colorful rainbow design. The advantages of such an umbrella are as follows:

1. Protection from the rain: The primary advantage of any umbrella is to provide protection from the rain, and a hand open rainbow umbrella is no exception. It can shield you from the rain and keep you dry.

2. Stylish design: The rainbow design of the umbrella can add a pop of color and style to your outfit, making it a fashionable accessory to carry around.

3. Easy to use: The hand open feature of the umbrella makes it easy to use. You don't need to struggle with complicated buttons or mechanisms to open and close it.
   

4. Portable: Hand open rainbow umbrellas are typically compact and lightweight, making them easy to carry around in your bag or backpack.

5. Durability: Umbrellas with sturdy frames and high-quality materials can withstand strong winds and rain, making them durable and long-lasting.

6. Can be used in different weather conditions: While primarily used to protect from the rain, umbrellas can also be used to shield from the sun or snow, depending on the type of umbrella and the weather conditions.

Overall, a hand open rainbow umbrella can provide practical benefits while also adding a touch of style to your look.