Spelling is in every case a cultural artefact, even for languages more phonetic than English. Such an orthography still needs to make choices about what distinctions to reflect in writing (e.g. should the orthography reflect regular and predictable allophony? voicing assimilation? final obstruent devoicing?) and there's no correct answer to this, there are only various trade-offs.

Colos to color was indeed part of a common sound change in early Latin (e.g. floses > flores), and led to new spelling, but many later substantive changes in Latin did not lead to any changes in spelling (e.g. the palatalisation of /k/ before front vowels). Similarly, English spelling used to change regularly to reflect changes in pronunciation, until Middle English, when it suddenly stopped and became largely fixed. And yet other languages continued to evolve orthographically after that point (e.g. major Czech spelling reforms in the 19th century). Why?

All of this is entirely cultural. In certain societies and at certain times, language users will prefer phonetic spellings, and in other societies and at other times they will prefer etymological ones. Sometimes spellings can evolve dramatically in a short span of time, at other times they seem eternal and utterly immovable. Language is deeply cultural.