How to find the right torsion Springs

I recently moved into a new home that is approximately 50 years old.
As a precaution I want to replace my garage door torsion Springs.
 Since I don't know the history of the door and the two torsion springs appear to be different sizes, When spring appears to be color-coded red and the other spring has no color coding.
I want to start from scratch.

The door is 7 feet high and 16 feet wide. The door weight is 240 pounds.
How do I determine which door spring to purchase.

Do you have a picture of the inside of the door? Make and model? Is the red on the cone or the wire itself?

I don't know the history of the door and the download tiktok video two torsion springs appear to be different sizes,

[size=13]It's a smart move to replace the garage door torsion springs for safety. To determine the right ones, calculate the door's [/size]Weight Lift torque requirements based on its weight and dimensions. You might want to consult a professional for precise measurements and spring selection to ensure your safety and proper functioning.