They weren't old only. They were also odd! I measured 13µF with my multi tester and I wanted to verify that unusual value, plus I wanted to find out the polarity. I was lucky to find this helpful colour chart that I uploaded on my webspace (original file to be found here).
Still I had trouble reading the colour code, because the paint was discoloured. I have problems seeing colours anyway. But also my wife wasn't sure about some of them. After a while we were sure what they must have been back in the days.
In this case the two capacitors are type B, but they differ a bit, because the third and fourth colour are swapped, also the dot-shaped marker is not on the middle ring (2), instead it is on the top. Very irritating!
1. brown (1)
2. orange (3)
3. blue (x1,000,000)
4. red (10V)
so: 13 x 1,000,000 (pF) = 13µF/10V
And as you hopefully all know it is very important to be sure about the polarity of the tantalum capacitors. These vintage ones had no special marker for the positive or negative leg. In the end it was proven that the anode (positive leg) is as it is shown in the picture of type B:
if the dot-shaped marker is pointing towards you and the legs are pointing upwards, then the left leg is the anode.
