The present disclosure provides a method for bonding parts, comprising the following steps
(a) Providing a two-component adhesive composition precursor, comprising Part (A) comprising at least one first dye and at least one epoxy curing agent;
Part (B) at least one second dye different from first dye and at least one epoxy resin;
(b) Mixing part (A) and part (B) of the two-component adhesive composition precursor to obtain an adhesive composition;
(c) Applying the adhesive composition onto a first part;
(d) Applying a second part onto the adhesive composition applied to the first part;
(e) Perform a first curing step at a first temperature, wherein the adhesive composition undergoes a first colour change;
Perform a second curing step at a second temperature higher than the first temperature, thereby fully curing the adhesive composition so as to obtain a structural adhesive bond between the first and second parts, wherein the adhesive composition undergoes a second colour change.