These packages are called MELF (metal electrode leadless face). They're usually used for resistors and diodes.
The fact that there are only two color bands/rings makes them less likely to be resistors.
See Electronic color code on Wikipedia.
The missing third ring could be interpreted as zero (black), making the red-yellow component a 24 Ohm resistor.
Vishay uses two-ring color codes to mark their diodes. Here's an example:
That would make the red-yellow component a BYM11-series 400V diode.
To be sure you should measure the components out-of-circuit.
When measuring components in-curcuit, you should be aware that other components might influence your measurements.
- low value resistances parallel to diode-under-test make them appear short-circuits
- capacitors parallel to resistor-under-test make them look short-circuit with rising resistance
These are examples, there are more combinations.
Components are best tested out-of-circuit to be sure. When measuring in-circuit cannot be avoided keep the above in mind and suspect components to be a certain type.
When measuring components that connect to mains make sure you wait long enough to bleed existing charge off of capacitors. You might use Low-Z mode on a multimeter to test such capacitors and help discharging them using the low input impedance. Be aware of dielectric absorbition