Colored matroid
{{Short description|Abstract structure with colored elements}}
In mathematics, a colored matroid is a matroid whose elements are labeled from a set of colors, which can be any set that suits the purpose, for instance the set of the first n positive integers, or the sign set {+, −}.
The interest in colored matroids is through their invariants, especially the colored Tutte polynomial,{{citation
| last = Zaslavsky | first = Thomas
| doi = 10.2307/2153985
| issue = 1
| journal = Transactions of the American Mathematical Society
| mr = 1080738
| pages = 317–347
| title = Strong Tutte functions of matroids and graphs
| volume = 334
| year = 1992| jstor = 2153985
| doi-access = free
}}. which generalizes the Tutte polynomial of a signed graph of {{harvtxt|Kauffman|1989}}.{{citation
| last = Kauffman | first = Louis H.
| doi = 10.1016/0166-218X(89)90049-8
| issue = 1–2
| journal = Discrete Applied Mathematics
| mr = 1031266
| pages = 105–127
| title = A Tutte polynomial for signed graphs
| volume = 25
| year = 1989| doi-access = free
| citeseerx = 10.1.1.183.2851
}}.
There has also been study of optimization problems on matroids where the objective function of the optimization depends on the set of colors chosen as part of a matroid basis.{{citation
| last1 = Maffioli | first1 = Francesco
| last2 = Rizzi | first2 = Romeo
| last3 = Benati | first3 = Stefano
| doi = 10.1016/j.dam.2007.04.015
| issue = 15
| journal = Discrete Applied Mathematics
| mr = 2351979
| pages = 1958–1970
| title = Least and most colored bases
| volume = 155
| year = 2007| doi-access = free
}}.