Rose-β-D-GlcU (6-Chloro-3-indolyl-β-D-glucuronide,cyclohexylammonium salt), also known as Salmon-β-D-GlcUA, is similar to X-GlcU, but the product of the substrate is a rose-colored (λmax ~ 540 nm) precipitate, which is easier to detect against the background of plant cells.