See how this looks.
For 1/2 inlay using a #5 (0.015" thick), the angle should be close to:
angle = arcsin(blade/wood) = arcsin(0.015/0.500) = 1.7 degrees.
The pilot hole (1/32" bit will be too small - try 3/64" or a #63 or larger bit) should be drilled so you are filling the darker of the two woods after assembly. If you want the insert to be proud, and if inserting from the top, then increase the angle a bit.