1. Sewing machine repair: If there is a small hole or damage in the T-shirt, it can be repaired with a sewing machine. Choose a line with similar color to the T-shirt, and sew the damaged part to ensure that the repaired part matches the original part.
2. Dyeing: If the T-shirt fades due to wear, you can consider re-coloring it with dyes. Choose a dye similar to the color of the T-shirt and dye it according to the instructions of the dye to make the color of the T-shirt more uniform.
The above suggestions are for reference only. If you have any questions about garment restoration, it is recommended to consult a professional tailor or laundry.