Band colors are not universal. One brand’s “medium” can feel different from another’s, and exact force can change with stretch length. Use color as a relative guide only within the same product family.
Start below your maximum
Choose a band that allows a smooth setup and a controlled return. If the band pulls you out of position or snaps back faster than you can control, use a lower relative level.
Check the full planned range
The right starting level should work through the entire movement you intend to use. Do not judge it only at the easiest point.
Use repeatable form as the signal
A practical level lets you repeat the movement without shortening the range, rushing the return, or bracing against nearby furniture.
Inspect the band every time
Look for cuts, thinning, tackiness, damaged seams, or surface changes. Replace a damaged band instead of trying to work around it.
Record the product and level
Because colors differ between families, write down the exact product and relative label that worked for the routine.