A widespread strategy for producing structural coloration in plants involves arranging cellulose microfibrils in the cell wall into a helicoidal architecture. However, the mechanism underlying this organization is not well understood. This work focuses on studying the interactions between cellulose nanofibrils and hemicelluloses, specifically xylan, using molecular dynamics (MD) simulations. The main objective is to investigate how the substitution pattern on xylan affects its adhesion to the cellulose surface, both hydrophobic and hydrophilic. Three model xylan chains with different substitution patterns are studied: one without any substitution (naked xylan), one where every other xylose unit is acetylated (acetylated xylan), and one acetylated model with a glucuronic acid group. In the literature, there are speculations that acetylated xylan adheres more strongly to cellulose than naked xylan. However, quantitative calculations of the work of adhesion in such cases are lacking. In this work, we not only examine the conformational differences between different xylan structures on the cellulose surface but also calculate the work of adhesion for each xylan model using MD simulations. Our results show that, contrary to common beliefs about xylan-cellulose adhesion, there is no significant difference in the work of adhesion between naked xylan and acetylated xylan. Acetylated xylan exhibits only slightly higher adhesion than naked xylan, with this effect being more pronounced on the hydrophilic surface of cellulose. Additionally, the presence of a glucuronic acid group results in slightly stronger adhesion compared to acetylated and naked xylan on the hydrophobic cellulose surface, while having little impact on adhesion to the hydrophilic surface. Overall, we conclude that xylan adheres to the cellulose surface in any form, providing chemical and structural flexibility that allows xylan to tune its molecular properties while maintaining its key interactions with cellulose.