Well, I mean, British abolitionism was much more influential than American abolitionism. So that's one place to start (which also means that that's a very fitting analogy, after all).

Throughout the early nineteenth century British officials were crucial to undermining the slave trade, leading up to the abolition of slavery in the British West Indies in the early 1830s. The West Africa Squadron, for example, patrolled the Atlantic to try to curb the travels of slave ships (haven't really looked through this page to see if it's completely accurate, but at first glance it seems informative). British abolitionists were crucial to ending slavery in British territory, of course, but in a weird combination of imperialism and abolitionism also used the empire's considerable political and economic might to influence abolition in other countries and territories. David Turnbull, British consul to Cuba, was a prominent abolitionist and was eventually tried (and either killed or exiled, can't recall at the moment) for allegedly providing support for the 1844 slave conspiracy to revolt remembered as La Escalera. See: Robert Paquette's Sugar is Made With Blood.

For something a little later in the century, see this primary source book on British Abolitionists and Brazil (disclaimer: I personally haven't read it yet, although I'll most likely get to it at some point) http://books.google.com/books/about/Joaquim_Nabuco_British_Abolitionists_and.html?id=GEJIAAAAYAAJ

So my area of study are the Arab territories, which for the most part fit a colloquial definition of "colonies" but not many of the strict definitions of the time (Egypt was a protectorate, the WWI gains were 'mandates.)

In this region the answer is yes, absolutely. World War I, in particular, produced a whole range of administrators who were hugely sympathetic to the Arab cause: T.E. Lawrence, Gertrude Bell, St. John Philby, Percy Cox, Glubb Pasha. All of whom have really interesting lives, often defined in political contrast with more bellicose administrators or officials of the empire.

Part of the problem though is that even "bad" policy makers were some of the truest believers in the positive effects of empire. Lord Cromer, who was instrumental in the occupation of Egypt in 1882, uses his book on the subject to absolve Britain of any faults while very much justifying himself in terms of a sort of Christian charity/white man's burden sort of thing.

His contemporary Wilfrid Scawen Blunt, however, in his "Secret History of the Occupation of Egypt" is scathing in his criticism of British policy and wholeheartedly supported the Urabist revolt. Cromer, in return, actually blames Blunt for pushing Britain towards occupation through his own political naivete.

So with hindsight it's not such a crystal clear issue, but yes, there were very much officials in the empire who believed in the causes of the people they ruled and tried to support them and help them to independence or to avoid British hegemonic control.

edit: mistype.