"Manic Panic Hair Dye Semi-Permanent Hair Color 4oz (Rockabilly Blue)" is another popular shade offered by Manic Panic. Here are some key details about this product:

1. Semi-Permanent: Manic Panic hair dyes are known for being semi-permanent, which means the color gradually fades with each shampoo. The longevity of the color depends on your hair's starting color, hair type, and how often you wash it.

2. Color Description: "Rockabilly Blue" is a vibrant and intense blue shade that is inspired by the rockabilly subculture, known for its retro and edgy style. It offers a bold and striking look.

3. Bleaching: For the best results, especially with shades like "Rockabilly Blue," it is often recommended to bleach your hair before applying the dye. Lightening your hair helps the color to appear more vibrant and true to the shade on the packaging.

4. Hair Type: Manic Panic hair dyes are generally suitable for most hair types, but they work best on pre-lightened or blonde hair. If you have darker hair, you may need multiple rounds of bleaching to achieve the desired color.

5. Temporary: Manic Panic hair dyes are temporary, so you can experiment with different colors without a long-term commitment.

6. Application: You can apply Manic Panic hair dye at home. It's essential to follow the instructions provided on the packaging, use gloves, and take precautions to prevent staining of your skin and clothing.

7. Vegan and Cruelty-Free: Manic Panic products are known for being vegan and cruelty-free, which is appreciated by those who prefer ethical and animal-friendly products.

The longevity of the color can vary based on factors such as hair porosity, your hair care routine, and the specific color used. To maintain the vibrancy of your Manic Panic hair color, it's recommended to use color-safe and sulfate-free shampoos and to wash your hair with cold water.

Before applying the dye to your entire head, it's a good idea to conduct a strand test to ensure you achieve the desired results. If you have any doubts or concerns about using the product, consider consulting with a professional hair colorist for guidance and expertise.