The combination can indicate a gas-safety concern requiring assessment. Do not rely on colour alone to declare combustion safe or unsafe.
What the observation means
Spills and cookware conditions may affect observations, but an owner should not compensate by modifying the burner. The exact change and associated deposits are useful evidence.
A useful next step
Stop using an abnormal appliance and contact an appropriately qualified professional. For a gas emergency, use the emergency service. Do not clean away every trace before describing the issue or repeatedly light the burner to see whether the colour improves.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.