Clean Oil Still

Hi,
Ive recently serviced my 300tdi engine by changing all filters and engine oil using Morris 15w-40 (link further down). I have noticed after 105 miles of using this oil, it is still yellow just like out of the can and im a bit concerned of weather the oil is suitable or doing its job correctly. As i believe diesel engines tend to make their oil black almost instantly after a service due to something do with carbon. The engine seems to be running fine, but i just want to check just incase as im doing a 250 mile round trip the weekend. I have also used a texaco diesel additive. Thanks alot!

Link for oil:
Magnol 15w/40

I cant answer the turning black question but I always use cheap 15w/40 mineral oil in my 300tdi engines. I have never used an aditive. I have driven many 400 miles round trips... Morrisons, Asda, Tesco all do similar oil 'suitable for turbo diesel engines' prices vary but about £12 for 5ltrs worth a look next time you pass.
15w/40 is fine (IMHO)....mine is black when I change it after 5k. Never needed to top up between changes.

Wonder if the aditive you use is removing the carbon and you have a clean engine? I did read that carbon deposits are normal and some say best left?

My brand new TD5 engine has done almost 200 miles now and the oil is still clean.
Was the oil you drained out black?

The reason the new oil turns black on an engine that you've just drained dirty oil from is because you can never get all the dirty old stuff out. Even using a flushing oil you'll never get it completely clean. The black is carbon which acts as a lubricant so dont be too hasty about getting it all out.