Theoretical color–color diagrams showing the effect of SMS hosted in young clusters compared to normal SSPs. Top: m_F336W − m_F435W vs. m_F275W − m_F336W color–color diagram. Bottom left: m_F435 − m_F555W vs. m_F275W − m_F336W color–color diagram. Bottom right: m_F435W − m_F555W vs. m_F336W − m_F435W color–color diagram. Yggdrasil models with solar metallicity and different covering factors are shown as blue (f_cov = 1) and yellow (f_cov = 0) lines. After 10 Myr, the f_cov is not relevant because the cluster is expected to be gas free. Therefore, models with different f_cov produce the same color indices and are therefore seen as a single brown line. The young cluster model from Martins et al. (2020) is shown as a large green dot. Different SMS+Cluster and SMS models are shown in red (A2), blue (A4), and magenta (B3) triangles and stars, respectively. For the cluster and cluster+SMS models, the transparent symbols are models without including the nebular emission while the dark ones are with nebular emission. The arrow in the top right corner shows the reddening vector. The length of the reddening vector corresponds to E(B − V) = 0.2 with the Milky Way extinction law (Cardelli et al. 1989). All magnitudes and colors are given in the AB magnitude system.