The photoluminescence features of Eu3+-, Tb3+-, Tb3+/Eu3+-alginate aerogel (hydrogel and alcogel) and Eu3+- alginate xerogel hybrids were investigated. The Eu3+-alginate aerogel and alcogel exhibit the highest D-5(0), quantum efficiencies (9.9 and 8.2%, respectively), while the hydrogel and xerogel have lower values (5.2 and 5.6%, respectively). The Tb3+/Eu3+ hybrids are multiwavelength emitters in which the emission color can be tuned across the chromaticity diagram from the red toward the yellowish-green spectral regions, crossing the white area by selecting the excitation wavelength.