Integrated Access and Backhaul (IAB) is a new standard for multi-hop 5G networks. It allows to use cellular frequencies for both backhaul and access purposes. Furthermore, wireless backhauling reduces deployment costs for cellular network densification compared to fiber. However, the fact millimeter Wave (mmWave) frequencies have shorter range and considering the additional interference from backhaul links, the deployement of such a solution is a complicated issue. In our vision, a solution for frequency allocation using a graph coloring approach is key in improving performance. In this paper, we propose a semicentralized algorithm where the IAB-Donor computes the pairs of interfering nodes in the network to determine conflicting frequency usage. Nodes are then allocated specific bands and can locally adjust them to communicate with their children. Simulation results show that the proposed solution is more than 50% efficient in terms of throughput compared to a centralized allocation by link coloring.