  We analyze the distribution of the chromoelectric field generated by a static
quark-antiquark pair in the SU(3) vacuum and revisit previous results for
SU(2). We find that the transverse profile of the flux tube resembles the dual
version of the Abrikosov vortex field distribution. We give an estimate of the
London penetration length of the chromoelectric field in the confined vacuum.
We also speculate on the value of the ratio between the penetration lengths for
SU(2) and SU(3) gauge theories.
