give us a picture, I'll try to help.
I wouldn't worry about the beige looking myc, it happens....
In my experience 99% of what goes wrong, starts with the syringe makeing process.
Unsterile syringe contents will contaminate 9 times out of 10, if not more.
Also not flameing the needle in between jars, is asking for it.
Injection of lots of spore or liquid mycelium is another baddy, the more stuff you squirt into your sterile jars, the higher the statistical odds gets for intruducing contaminants, aim for 1ml or less.
If you take care of that, you should have 0 problems.
Once in the jars and past the 4 day mark, you should realy be all good. Provided you make provision for adequate gas exchange. Especialy important when working with grains. I find a simple 10ml hole plugged with aquarium filter floss (polyfill), is the best for this. Twyvek can be used but I find it hard to get a nice seal that prefents dust and airborne spores getting past. DON'T use cotton wool, it gets soggy, is crap hard to get a needle through, and is made of stuff the shrooms can eat.
I cant even remember when last I had a contam, and I'd hate to say how many jars I make in a month.
Of course, and this is personal opinion, which could be influenced by environmental factors...I think cakes are a waste of time.