The power sword was quite easy. First, I covered the miniature so I wouldn't accidentally paint over the parts that didn't need painting. I used a little plastic bag, covered the mini, sticked the sword through it and sealed it with tape.
I used four colors in total. A base color of Vallejo Air Color 71004 Blue, 3/4 of the sword with Vallejo Game Color 70844 Deep Sky Blue, 2/4 of the sword with Vallejo Game Color 70961 Sky Blue, 1/4 of the sword with Vallejo Air Color 71001 White. The whole process took about 15 miniutes.
I cannot remember exactly what I did with the red. In total I did three different attempts on the miniatures. I tried to follow
this YouTube movie. I used other colors than shown in the video. I don't have many red in the Air Color range, so I mostly used thinned down Vallejo Game Colors. I remember using 70911 Light Orange for the final highlight and brown for the shadows.
The highlights applied with the airbrush are very thin. To get good coverage with red or orange on a darker base color you'll need to apply more than one layer. You might consider to work the other way around, starting with the middle or lightest color. For the final highlights I first sprayed with white before covering it with the orange otherwise I would need to spray way too much orange to get good coverage. The airbrush I used isn't very precise. It's smallest radius lies around 5 mm. This makes it hard to get that final highlight without covering the other layers. I think a better airbrush would make a difference.
Eventually I'm planning on doing another squat of 5 Ultra Space Marines. I think blue is a lot easier to get right. One thing I'll try to do differently is not to assemble them completely like I did with the Blood Angels. It'll be much easier to paint if you leave the arms off.