After crossing the Los Angeles River, the freeway then terminates at Colorado Street in Glendale.

(This segment of Shamrock Avenue was once part of an early alignment of US 66 and had been named Foothill Boulevard.)

It was moved to the Los Angeles County Arboretum and Botanic Garden during the construction of the 210 Foothill Freeway in 1970.

By the late 19th century, this part of Colorado had become so popular, it was becoming a traffic bottleneck, and as early as May 1900 there were public outcries to the City Council to widen the road.

It wasn't until 1929 that the City undertook the major and unprecedented task of cutting back the buildings along Colorado 14 feet (4.3 m) on each side.

This undertaking created a monumental amount of legal red tape as well as many engineering dilemmas which were handled with amazing results.

In the 1964 renumbering, LR 161 remained State Route 134 west of Pasadena, though this was being moved to the new alignment (now the Ventura Freeway); until the freeway was completed through Pasadena in the mid-1970s, Colorado Boulevard was still signed as State Route 134 between Orange Grove Avenue and Arroyo Parkway.

Colorado Boulevard is served by several bus routes, operated by Metro and suburban systems.

Metro Local line 180 serves most of Colorado Boulevard, running between Hollywood and Pasadena.

[6] Also, Foothill Transit line 187 serves parts of Colorado Boulevard, beginning in Old Pasadena.

[7] Metro has identified Colorado Boulevard as a potential bus rapid transit corridor, part of a line between North Hollywood station and Pasadena approved in 2016's Measure M. The bus rapid transit project would need to include removable components to allow for the annual staging of the Rose Parade.

[9] The street is mentioned in the 1964 Jan & Dean single The Little Old Lady (from Pasadena), with the protagonist described as the "terror of Colorado Boulevard."

It’s about a poor immigrant from Pakistan trying to make his way in America by working the graveyard shift at the Colorado Boulevard Chevron", When talking about the gas station across their road.