Roswell Conspiracies: Aliens, Myths and Legends
This could be Roswell Conspiracies: Aliens, Myths and Legends, a series of 40 half-hour episodes that originally ran in the 1999-2000 television season. It follows the adventures of The Global Alliance (a paramilitary organization based in Roswell, New Mexico, USA) as they maintain order and secrecy concerning alien activities on Earth.
The series has a large cast. The primary characters are Nick Logan (a white man) and Sh'lainn Blaze (a pale humanoid alien woman). One of the most frequently-appearing supporting characters is Jefferson Trueblood, a Native American man:

L-R: Jefferson Trueblood, Nick Logan, Sh'lainn Blaze.
Jefferson is a skilled hand-to-hand combatant and an expert in the use of weapons. His complexion is somewhat darker than that of the white characters, and he frequently wears metallic armor on his arms and legs.
Dorian Wyrick is another agent of the Alliance. His role in the series is less prominent than Jefferson's. Dorian is black, and he wears a full suit of armor:

Front L-R: Dorian Wyric, Sh'lainn Blaze, Nick Logan; Rear: Ti-Yet (a Yeti).
The Alliance is ethnically diverse, including also Middle Eastern (Nema Perrera) and Asian (Keung Ling) characters.

Rear L-R: Simon "Fitz" Fitzpatrick, Dorian Wyrick, Jefferson Trueblood.
Front L-R: Sh'lainn Blaze, Nick Logan, Nema Perrera, Keung Ling.
The show's theme and title sequence starts at 0:17 in this video: