I need to keep better notes ;-( Only tried Rochelle Salts a couple of times, so not much knowledge there. Initial color varies from gray/black for Sodium Acetate to reddish brown for Sodium Citrate. Stevens speculates that color difference due to silver particle size with Acetate producing larger particles. The final color, though, is primarily dependent on toner with Citrate dev'd print in gold-toner yielding a gray/black. Exposure times vary between the two, but this is where my notes/recollection fails me. The Tartaric Acid acts as restrainer with clearer whites. As with pt/pl, the Potassium Dichromate additive enables contrast control.