Hi Rei,
My daughter has a slight green tinge of colour on her nose, between her eyes and I asked my doctor about it a while back and she was not worried or concerned about it. If you are concerned and thinking about giving a medicine I would check with your doctor first (I would always check about any type of medicine, even a vitamin or anything herbal as a baby's system is so delicate). As for your baby jumping at sound I find many babies a little jumpy when they are young- they get easily startled.
More likely the reason for your baby's short naps is that their average nap cycle is 45 minutes long and when many babies wake up they are not able to re-nap. My daughter has 3 short naps in the day and if I'm lucky, one longer one. If sounds like you've had some success with rocking and patting him, have you tried to do this with him laying down in his crib/bassinet? I would try this next, put him down when he's awake (not crying), pat his bottom/side and softly sh/sh/sh him, it may help if there are not toys/distractions hanging above him or any music. Put him down before he looks too tired- if you wait for him to yawn many times it will be too late, he may be overtired by then. It may not work the first time but if you do this repeatedly it should.
Give us an example of a typical day's schedule. Also, how many hours in total is he sleeping in a 24 hour period? The experts will probably need to know this to help out.