The pigments separate in the glue if you have not used the glue for a long time. Shake the bottle of glue vigorously, at least 2 minutes before dripping. You will probably need to discard the first or more drops because the glue in the neck of the bottle will not mix well. If the glue still does not mix properly and becomes uniform, try shaking the contents even more. If you do not succeed at all, contact us.