Light color alone is no quality. What matters to the boiler are moisture, ash content, abrasion resistance — and whether bark, sand or binder is in the raw material.
ENplus A1
Class A1 is the household guide value: low ash (usually up to ~0.7 %), limited moisture, stable diameter. The certificate is tied to the manufacturer and the supply chain, not to the nice bag photo.
DINplus
A German label with similar laboratory limits. In practice, both answer the question: «Is this fuel for a modern boiler — or a sawdust surprise?»
Without a standard
An uncertified batch can burn well — or clog the burner, form sintered ash and crumble to dust in transit. For an automatic boiler, that's an expensive lottery.
Useful is the certificate number — and don't confuse the marketing logo with an entry in the scheme register.