you can't
i'm kidding
there are way too many ways to do it
you can select a face and assign a new material to it
you can use ramp shaders
you can use texture mapping (the most common way to add detail without increasing geometry)
use solid texture synthesis (not a perfected technique yet)
you can assign procedual solid textures (not as fancy as solid txture synthesis and takes a long time before you get something reasonable)
you can't use vertex colouring, which i think is really weird
in short your answer is to assign materials to faces or use texture mapping
i figure you dont know what that means (or you wouldnt be asking) so i direct you to the inbuilt tutorials that come with maya and this one here at this site
https://www.simplymaya.com/movie_page...html?tut_id=94
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D