rubiginose

ru·big·i·nous

 (ro͞o-bĭj′ə-nəs) also ru·big·i·nose (-nōs′)
adj.
Rust-colored; reddish-brown.

[Latin rūbīginōsus, from rūbīgō, rūbīgin-, rust, from rōbus, red; see reudh- in Indo-European roots.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

rubiginose

(ruːˈbɪdʒɪˌnəʊs)
adj
rust-coloured or rusty
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014