It only seems to be without phonetic relevance because in English we think of the word sounding like "chrome with a 'c.'"
Koine Greek is a much older form of the Greek, in which the New Testament Bible was written. If you compare the sounds of the Koine Greek alphabet to its current sounds, it really has changed a great deal over time.
With χρώμα you really hear more of a voiced breathing 'h' sound here instead of a 'c' like in the English translation. Koine Greek used apostrophes before words to denote this breathing sound beginning a word. That's one of the things that changed. So now the 'χ' sounds more like an 'hkr' here, rather than just hard k.
I don't know Koine very well and just started the modern Greek this year. So I'm no expert. Just offering a tip to explain the 'evolution' of the language over the last 2 centuries. Hope that helps a bit.
This section is to teach you what the Greek alphabet looks and sounds like. Look at these links for help
This is the Skill to help you learn the Greek alphabet. We can't make very good sentences if you don't know the alphabet so we use some short words.
See this list which you might find helpful.
THE MODERN GREEK ALPHABET and HOW TO GET THE GREEK KEYBOARD
And these tips:
TIPS TO MAKE LEARNING EASIER + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links.