Visible spectrum of 2023 FW₁₄ obtained with the 10.4 m GTC (in orange) and its best taxonomical match from the M4AST online tool, Xc-type (in red). The hatched gray area fills the entire domain between the mean B-type and D-type classes as defined by DeMeo et al. (2009). The blue squares correspond to two visible spectra published in Borisov et al. (2018) (labeled B18) of the other known L₄ Mars trojan, (121514) 1999 UJ₇. The third spectrum of 121514, shown here as green triangles, was published in Rivkin et al. (2003) (labeled R03).