If you want to dye your locs red without bleaching, then you can opt for a semi-permanent or temporary hair dye that is designed to work on darker hair shades. These dyes are meant to deposit color onto your hair without lifting your natural hair color. Some good options include henna, beet juice, and cranberry juice. However, keep in mind that these natural options may not provide the intensity or longevity of a chemical dye, so you may need to reapply the product more frequently. Additionally, if you have very dark or resistant hair, it may be more challenging to achieve a dramatic red shade without bleaching.