I use a mandolin slicer, slicing from the non-stem end until I reach the core, then de-core it and slice the rest the same way. This gives me fairly uniformly thick rings (thin or thick, depending on the slicer settings), and if I want smaller pieces, I just chop those up as needed.
Why worry about seeds? I use all the seeds from chili peppers, and no one I fed has died yet.
It is so simple I’v never given it much thought… but just take a knife (usually a Chef’s but it really doesn’t matter) and cut through the sides up to the stem. Break it open and you will have one half with the core and the other without. Grab the core and pull it out… you now have two halves with very few seeds. Rinse and pinch out any remaining white parts.
I gave up on a video posted up thread when it got to step 8 and still wasn’t done. It isn’t rocket science.
I used this method. It worked pretty well. Thanks, Cub Mistress.
you’re very welcome 
I don’t think there are blue peppers, but I have seen purple.
This is exactly what I do. I learned it watching Martin Yan (“Look at that!”). That guy is awesome.
Yup, quite pretty, although the color is only the skin (insides are green) and the color is lost in cooking, so use raw for best effect.