The correct spelling of this word is actually "more paled" not "more pale". The reason for the confusion is due to the pronunciation of the word. The word "pale" has two possible pronunciations: /peɪl/ and /pæl/. When the pronunciation is /peɪl/, the past tense and past participle become "paled" instead of "paled". Therefore, when we want to say that something is becoming even more pale, we would use the spelling "more paled" to indicate the correct pronunciation.