Hello there!

Imperialism was most pronounced in the last decade of the 19th century. All big European industrial powers shared this common foreign policy, especially France and England, the Netherlands and the German Kaiserreich.

A key characteristic of the imperialist ideology (which percolated the status quo and the general opinion) is a strong sense of mission (cultural, political).

In cultural science, the idea of "Social-Darwinism" was helt by the intellectual elite. Today it's seen as a pseudo-science and it included theses about superior races and people of color are naturally supposed to be ruled and in fact they should be thankful to the "white masters".

I don't want to get off track here, but if you go back into the 19th century, you find out that some things which Hitler later incorporated were already present, not only in the Wilhelminian Germany, but also in the other industrial nations.

Since you asked especially about the British Empire, they had the motto of "Greater Britain". Important projects were in India, the construction of the Suez-Canal (1869), the systematic expansion predominance in Africa and Asia (motto: from Capetown to Cairo, from Cairo to Kalkutta), the control over the Mediterranean Sea (Gibraltar, Malta, Cyprus) and the construction of military bases around the world.

So, I would say, the British Empire was racist, but the other industrual powers as well. This mentality of increased Nationalism and Chauvinism created an athmosphere for WW1.

I think there isn't much to defend about the racism of that time (other than it was status quo), but one should be careful about measuring with different sets of scales, for example a debate whether France or England were "more racist".

I hope this answer was of any help, excuse my grammar since I'm no native speaker. Also, I hope my statements weren't too provocative. Especially the part about Hitler is a strong oversimplification.