Dunedinia decolor is a species of Linyphiidae spider that is endemic to New Zealand.
This species was described in 1988 by Alfred Frank Millidge from female and male specimens. The holotype is stored in Otago Museum.
The female is recorded at 1.80-1.95mm in length whereas the male is 1.75-1.95mm. This species has a brown carapace that is darkened along the margins and fovea. The legs are yellow to brown. The abdomen is white on the dorsal surface with a black chevron pattern.
This species is only known from the South Island of New Zealand.
Under the New Zealand Threat Classification System, this species is listed as "Not Threatened".