Believe it or not I have a Masters degree in art and a degree in Architecture.
I think that colour is fantastic. To answer your question I spelled color the proper way.
Credit to Wkipedia given.
http://en.wikipedia.org/wiki/American_and_British_English_spelling_differences#-our.2C_-or
Excerpt of above Wiki link------
-our, -or[edit]Most words ending in an unstressed -our in British English (e.g. colour, flavour, harbour, honour, humour, labour, neighbour, rumour) end in -or in American English (color, flavor, harbor, honor, humor, labor, neighbor, rumor). Wherever the vowel is unreduced in pronunciation, e.g. contour, velour, paramour and troubadour the spelling is the same everywhere.
Most words of this kind come from Latin non-agent nouns having nominative -or. These words were first borrowed into English from early Old French and the ending was spelled -or or -ur.[5] After the Norman conquest of England, the ending became -our in Anglo-French to try to represent the Old French pronunciation,[6] though color has sometimes been used in English since the 15th century.[7] The -our ending was not only used in English borrowings from Anglo-French, but was also applied to the earlier borrowings that had used -or.[5] After the Renaissance, new borrowings from Latin were taken up with their original -or ending and many words once ending in -our (for example, chancellour and governour) went back to -or. Many words of the -our/or group do not have a Latin counterpart; for example, armo(u)r, behavio(u)r, harbo(u)r, neighbo(u)r; also arbo(u)r, meaning "shelter", though senses "tree" and "tool" are always arbor, a false cognate of the other word. Some 16th- and early 17th-century British scholars indeed insisted that -or be used for words from Latin (e.g. color[7]) and -our for French loans; but in many cases the etymology was not clear, and therefore some scholars advocated -or only and others -our only.[8]
Webster's 1828 dictionary had only -or and is given much of the credit for the adoption of this form in the United States. By contrast, Johnson's 1755 dictionary used -our for all words still so spelled in Britain (like colour), but also for words where the u has since been dropped: ambassadour, emperour, governour, perturbatour, inferiour, superiour; errour, horrour, mirrour, tenour, terrour, tremour. Johnson, unlike Webster, was not an advocate of spelling reform, but chose the spelling best derived, as he saw it, from among the variations in his sources. He preferred French over Latin spellings because, as he put it, "the French generally supplied us".[9] English speakers who moved to America took these preferences with them, and H. L. Mencken notes that "honor appears in the 1776 Declaration of Independence, but it seems to have got there rather by accident than by design. In Jefferson's original draft it is spelled honour."[10] In Britain, examples of color, flavor, behavior, harbor and neighbor barely appear in Old Bailey court records from the 17th and 18th centuries, whereas there are thousands of examples of their -our counterparts.[11] One notable exception is honor. Honor and honour were equally frequent in Britain until the 17th century;[12] Honor still is, in the UK, the usual spelling as a person's name.
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Depending on where you're from we all pronounce (your home country/area accent) words differently.
The dictonary you use plays a part too.
The spelling is right no matter which way you type it. Just depends on where you're from
Keeping track of trends is a habit of mine.