This is your typical tourist shot, the sunset looks great to your eye but try and capture the shot with a camera and you have one nasty bright sun in the photo. Even this took a bit of an effort to get a little detail on the observatories despite that setting sun!
The colours in the sky for 20 to 30 minutes after sunset are simply awesome even if I hate that word! It's worth hanging around for that long just to get a good photo from Mauna Kea's summit. It's worth the wait even if you freeze your bollocks off (apologies to the ladies).
And put that flash away. I can't believe the number of people who take pictures of a Mauna Kea sunset and have the flash turned on. What on earth are you hoping to accomplish?
Sorry, bad day, I just needed to vent. I hope you're having a great weekend and had a wonderful and spooky Halloween!