Match the sensor generation
Chamberlain identifies an amber sending light and a green receiving light on its 041-0136 and 41A5034 pairs. Its older 41A4373A pair uses two green lights. These examples explain why a color rule from a different installation can be misleading. They are not a color chart for every opener brand or replacement sensor.
Keep the observation separate from the diagnosis
For a service request, record the opener model, the color on each side and whether the condition is steady or intermittent. A photo taken from a safe position can show which light you mean. Describe when closing stops and whether anything in the opening changed. A light alone does not establish which component needs replacing; the technician also needs the equipment history and the actual closing behavior.
Do not defeat the protection to get the door closed
Keep people and vehicles clear while a closing problem is unresolved. Do not tape over sensors, bypass their wiring or change the opener force to compensate. If the door is crooked, has a loose cable or has damaged hardware, stop operation and request door service rather than treating the problem as a sensor-only issue.
Your questions
Is an amber light automatically an error?
No. On the Chamberlain sensor pairs identified above, amber is the normal sending-light color. Use the model-specific instructions and the light's behavior, not its color alone.
Should I buy new sensors because mine are different colors?
Different colors alone do not establish failure. Identify the existing pair before ordering; compatibility and the cause of the closing problem still need to be checked.
Is the flashing lamp on the opener the same as a sensor LED?
No. Tell the technician whether you mean a small light beside the floor or a light on the overhead opener. They are different observations and may follow different diagnostic instructions.