Here's a Breakdown of all the lines and their numbers

Metrolink (Commuter) Routes
M100 Series (Dark Blue, Follows Pacific Coastliner)- Venturia Line
Sandres -> Downtown Venturia via Simi Valley
M200 Series (Green) - Central Valley Line
Sandres -> Lake Havok
M300 Series (Purple) - San Bernin Line
Sandres -> Downtown San Bernin
M400 Series (Light Orange) - Riverdale Line
Sandres -> Downtown Riverdale
M500 Series (Dark Blue, Follows Pacific Coastliner) - Orange County Line
Sandres -> City of Orange
M600 Series (Dark Red) - Perris Desert Line
Sandres -> Perris Downtown
M700 Series (Yellow) - South Venturia Line
Sandres -> Downtown Venturia via Glendon
M800 Series (Pink) - North Venturia Line
Sandres -> Downtown Venturia via Santa Karina Valley
M900 Series (Dark Green) - East Riverdale Line
Riverdale -> San Bernin Downtown

Amtrak (Long Distance/Higher Speed) Routes
All Dark Blue
DW100 Series - Desert Wind
Sandres -> Las Vegas via Riverdale
A600 Series - Pacific Coastliner
Santa Diego -> Sandres
A700 Series - Pacific Coastliner
Santa Diego -> Santa Barbera
A800 Series - Pacific Coastliner
Sandres -> Santa Barbera