According to Weber & De Beaufort (1913: 13), the colouration of S. formosus is dorsally dark green, the sides
and ventral sides silvery or golden green, sometimes with longitudinal rows of oblique dark patches, shining
through the lateral scales (shown in their black & white drawing of the species). Fin membrane bluish, the rays
golden brown. According to Dr Isbruecker (Zoological Museum Amsterdam, now Naturalis Biodiversity Center),
the ZMA collection holds only two specimens that were present before 1913; one from Borneo (from Bleeker’s
collection) and one collected in Palembang, Sumatra, in 1908. These are the localities marked with an explanation
mark in Weber & De Beaufort (1913: 13). The authors thus did not see live specimens and their colour description
must have been compiled from descriptions of previous authors.