Context. JWST has revealed galaxies at z > 10 with extremely blue UV-continuum slopes approaching βUV ≲ -2.4, and low inferred dust content. At similar redshifts, JWST and ALMA reveal dusty massive systems reaching βUV ≳ -1. Aims. We explain blue monsters and red monsters at z ≳ 10 as different outcomes of supernova dust retention in clustered star-forming systems and connect this bimodality to dusty massive galaxies at z ≃ 6--7. Methods. We modeled dust removal in a cluster-dominated regime through cloud-scale mechanical blowout followed by breakout from stratified high-redshift disks. The shock-processed dust mass retained in the UV-attenuating layer was converted into a UV-continuum slope using absorption opacities derived from 3D hydrodynamical simulations of clustered supernovae in porous molecular clouds. Results. In compact gas-rich galaxies, efficient cloud blowout and disk breakout reduce the retained dust fraction to blue monster levels, yielding βUV ≲ -2.4. Higher stellar masses increase the retained dust column and produce red monster-like systems with βUV ≳ -1.5, reaching βUV ≃ -0.5 when radiative losses weaken large-scale driving. Conclusions. The transition depends on whether clustered-supernova ejecta cross both the natal cloud and the galactic gas layer. Supernova dust production, shock processing, radiative losses, and mechanical venting can jointly explain UV-bright dust-poor galaxies and red dusty massive systems across 6 ≲ z ≲ 14.