Need help!

Not really sure what this is at the top never happened befor, but this is only my third small batch. I'm just getting into the hobby still learning new things! If anyone has ever seen this before and can help would be gladly appreciated!

Do you mean, the funky off colour? Or, the blow off tube in general?

it appears to be a normal krausen, but are you referring to something besides that, like the yellow color?

Well I put my airlock in it the night of brewing and after couple hours the pressure was too much I switched to the blow off tube to allow more air flow. After beer settle there was that stuff left at the top of carboy and a little in tube. I was not sure if I should be worried or just let it go and transfer it to a 2nd fermenter. It's only been three dad so far. And is the color bad thing? Like I said I m not to experienced with this so anything will help! Thanks guys

It looks normal to me; it's hard to tell what the yellow stuff is, but krausen typically looks pretty nasty in general. When a beer is fermenting, a krausen can really start to form and get pushed out the top (hence the blowoff tube is useful; otherwise it'll clog the airlock, build up a lot of pressure, and pop the airlock out causing a big mess). The krausen will stick to the sides of the carboy/container and inside the blowoff tubing. It looks like that's what you're seeing.

That stuff is the "Krausen", its mostly foam from dead yeast and unusable proteins that gets stuck to the side of the carboy. Surely you've seen it if this is your 3rd batch. The Krausen is normal, let it be.

But, I have never seen that yellow colour before.

What yeast did you use?

What did you use inside your airlock? Sanitzer? Idophor? They might be the culprit if the krausen crept up inside the airlock, as is common with one gallon batches, and may have caused the off color. Sanitizer solutions like Starsan are fine, but I wouldn't consume it if you filled the air lock with an idophor solution.

Does it have an off smell? Or does it smell like the yeast you put in?

To be honest i'm not 100% sure what the yeast was. i used the Brooklyn brew shop kit and just ordered another mix but i'm pretty sure they use muntons dry yeast. I have seen this at the top of carboy last brew but nothing to this extent that's why i got worried. Thank you both for your responses.

also no bad smells, has a nice hoppy smell to it!