Hey Bob- when watching the Kings nip and spit the blue sacs so quick and squishing the eggs I have long wondered if they just kinda like the taste of the milky inside of the eggs and want nothing to do with actual food ..
  Have watched the same males do this - and use up most of my blue sacs lol- repeatedly. Dont care bout the sacs-- love the show.
 We know they have shut down on eating- specially upriver where I have watched the show- just have always wondered about the taste in their mouth being the reason.
  Might be why you too have observed them doing the subtle quick  hitting.
 One may think that if it were just an instinctive hit they might just grab it or hold on a bit more.
  Phood for thought.
  Makes me wonder bout scented baits - and if I am sane or not.

Since we can not communicate with the salmon we can only guess as to what makes them hit one color and not another,or hit anything in front of them,or hit nothing at all at times.I've tried talking to them but then I get strange looks from Rich and just spank them and send them on their way

 Talk to myself when fishing- sometimes  tell myself off pretty good too. Can get real nasty when missing a  hit or tangling a line.
 Sometimes take offense and ignore me for hours.

Have you ever used an egg loop to get your hook below the sac? Assuming you're putting the hook through the material now. Hook might stick every now and then, you never know.

Never tried it but am interested.

RT the fish I was talking about weren't nipping.
They would peel off from a pod,turn and follow the streamer downriver till they caught it then take while maintaining the same speed so you never felt anything while they chewed it for a couple seconds then let it go.

Hey --thats neat- would love to watchem do that kinda stuff.

The color thing is maddening and perplexing.  I know with steelhead all over the Great Lakes, steelies will prefer one color to another day to day, BUT. Pink will always take fish. Sometimes bright sometimes pale.  Not having all that much experince with Salmomn R kings I wonder if the same is true?  Maybe not pink but some color. Over years of watching Steelhead. inhale my egg/nymph and spit it before I can set the hook I wonder how often is that happening  when were fishing the water and not visible fish??   However when swinnging a fly and a fish latches on to "savor " it you should feel something. A change in the path of the swing, more weight, less weight on the line. One should feel sommething different. And when it suddenly feels different set the hook! 
 
July 1, 90 days to the opening of my Steelhead season.  And there's rain falling everywhere. Love to see that!

In the case I was talking about the fish was just going at the speed and direction of the fly.
They could mouth it for a couple of feet before spitting it out with no indication at all.
This was in the very early 80s with near zero fisherman on the river and water level at about 175 down in what became the DSR later.
No weight of any kind to deaden the feel.
It is amazing what we don't know is happening.
 
Color preference can change several times in a day.
 

Yup all good info and stuff to try and decipher what it takes to be top hooker..ugh did I really type that ..
Anyway, after 38 hrs being awake I think I may have an answer ..
It is, Ain't gonna catch no fish if you ain't fishin' ..
Well true that but all you guys have hit on all the points..
Seen it all, fish that I see turn , grab and continue downstream with out knowning > Sight fishing at its finest if you ask me..
Fish that refuse everything you throw at them.. Fish that will take anything you have in your box until you need to tie more estaz flies..
 And yes the Skunk on the SR !!
It's a tough game sometimes and the only advice from here is to keep playing the games we enjoy..
Have fun:
Sleep & Tuna