In a large bowl, combine soy sauce, hoisin sauce, honey, rice vinegar, sesame oil, five-spice powder, minced garlic, grated ginger, and red food coloring if using. Whisk until well blended.
Add the chicken thighs to the marinade, ensuring they are fully coated. Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or overnight for best results.
Preheat your grill or oven to 400°F. If using a grill, lightly oil the grates.
Remove the chicken from the marinade, allowing excess marinade to drip off. Reserve the marinade for basting.
Grill the chicken for about 6-7 minutes per side, basting with the reserved marinade, until the chicken is cooked through and has a nice char. If baking, place the chicken on a lined baking sheet and bake for 25-30 minutes, basting halfway through.
Once cooked, let the chicken rest for 5 minutes before slicing. Serve hot with rice or steamed vegetables.