Seedlings favor a blue-green spectrum light with a color temperature of between 5000K and 6500K. When your seedlings are growing outdoors, they would receive natural sunlight, which is what this kind of light imitates.
Therefore, get a grow light that emits a blue-green spectrum and has a color temperature of roughly 5000K–6500K if you want to keep your little sprouts happy and healthy. Your seedlings will return the favor by becoming robust and tall!