Colors of trees is since it´s founding FSC-certified: FSC® C005333
The worldwide independent and non-profit organization Forest Stewardship Council® (FSC®) promotes environmentally appropriate, socially beneficial and economically viable management of the world’s forests and thereby helps ensure the sustainable use of wood. When you buy FSC-certified goods, you can rest assured that the world’s natural resources are being used in a sustainable as well as socially, ecologically and economically balanced way.

For further information see:
FSC International Center
https://ic.fsc.org/