As a personal guess I would say your AC adapter is knackard or about to be knackard in the not so distant future.
If you put your hand on it see if its roasting hot.
The blue then red red red red red says to me the thermal cut out is cycling. It puts charge through (blue) then over heats cuts out and cools (the reds) then once cools puts charge through again which then overheats etc etc.
But looking at this article
Nabble - cheapbattery - Dell XPS M1330 Battery Q&A it seems like there could be a whole raft of issues going on under the hood.
Actually scrub the idea on the AC adapter after reading some more articles on that machine box it up and send it back to Dell looks like that model is a right lemon.