The composer, John Lunn, also composed the score for "Downton Abbey" (2010), which is why many of the musical themes are similar and nearly identical.
Throughout the series Amy only wears purple clothes, or black when she is in mourning, her sister Fanny wears only greens and orange/peach, and black when she is in mourning.
The green Spencer with cut-outs on the sleeves worn by Emma Pierson (Fanny Dorrit/Fanny Sparkler) at Marshalsea was the same costume Anna Chancellor (Caroline Bingley) wore at Netherfield in Orgulho e Preconceito (1995), Julia Davis (Elizabeth Elliot) wore at Kellynch Hall in Persuasão (2007), an extra wore at the London party where Annabella Milbanke meets Byron in Byron (2003), and Vicki Pepperdine (Ann Dobbin) wore in the park scenes in Vanity Fair (1998).
Russell Tovey (John Chivery) and Claire Foy (Amy Dorrit) appeared on "Being Human" (2008).
The tan striped gown with teal scallop trim at the hem Emma Pierson (Fanny Dorrit/Fanny Sparkler) wears to visit Mrs. Merdle (Amanda Redman) is the same costume Greta Scacchi (Mrs. Weston) wore in the final scene of Emma (1996). The same costume was also worn by a guest at the Easter Ball in Filhas e Esposas (1999).