Color adjustment methods and systems

A computer-implemented method for determining an adjusted sample coating formulation to match the color of a reference coating, said method comprising:

• (i) providing to a computer processor via a communication interface
• a digital representation of the sample coating containing color data of the sample coating and the sample coating formulation,
• a digital representation of the reference coating containing color data of the reference coating,
• a digital representation of individual color components containing optical data of individual color components, and
• a physical model configured to predict the color of the sample coating by using as input parameters the sample coating formulation and optical data of individual color components;
• (ii) determining—with the computer processor—the color difference between the provided color data of the sample coating and the provided color data of reference coating;
• (iii) determining—with the computer processor—the model bias of the provided physical model by
• predicting color data of the sample coating based on the digital representation of the sample coating, the digital representation of individual color components and the physical model provided in step (i), and
• determining the color difference between the provided color data of the sample coating and the predicted color data of the sample coating;
• (iv) minimizing—with the computer processor—the model bias determined in step (iii) by adapting the provided optical data of at least part of the individual color components present in the sample coating formulation;
• (v) determining—with the computer processor—the residual model bias by determining the color difference between the provided color data of the sample coating and the predicted color data using the optical data adapted in step (iv);
• (vi) calculating—with the computer processor—an adjusted sample coating formulation based on the color difference determined in step (ii), the adapted optical data of individual color components obtained in step (iv), the residual model bias determined in step (v) and the provided physical model;
• and
• (vii) providing the calculated adjusted sample coating formulation via a communication interface.