Your neon colour should work with your brand rather than fight against it.
Snow White creates a clean, contemporary look and works particularly well with minimalist retail interiors. Warm White gives boutiques and lifestyle stores a softer, more premium feel, while stronger colours such as Pink, Blue, Red, Green or Orange can make a much bigger visual statement.
If your branding already uses several colours, a multi-colour neon sign can reproduce that identity much more effectively.
The surrounding wall colour, shop lighting and products should all be considered when choosing the final colour.