Each Clonex product is colour-coded for convenience:- Green (1.5g/L IBA) – Ideal for softwood cuttings- Purple (3.0g/L IBA) – Best for medium wood cuttings- Red (8.0g/L IBA) – Perfect for hardwood cuttings. If there is callusing but no root formation this indicates the hormone level is too high, and a lower hormone concentration should be used.