to be honest it looks like a type of aloe we had in Arizona and they did have this yellow inside. It is a yellow flowering one, and if you are doing the watering as you say it might be ok. The cut open leaf looks pretty healthy, and just like this other one. Since you got it awhile ago, you might have got this different type. Check this link I posted here, the aloe you have may be this one. Here is a link that might be useful: Aloe vera or Aloe barbadensis?

There are three "major" medicinal Aloes: Aloe arborescens (seriously people, if you live in SoCal, use this!), Aloe saporina, and Aloe vera. These are the standard, "put it on what hurts" Aloes, good for burns, scrapes, and other topical ailments. There are many other species used for other reasons (purgatives and laxatives are common!). In reality, most stuff sold at supermarkets is just the inner gel of the leaf with some other stuff mixed in. The thing is, most of the "medicinal" compounds are in the yellowish sap than runs more in the skin of the Aloe than in the middle, clear gel. If you've ever used real leaves instead of a supermarket bottle, you'd have found that it is much more effective, but leaves a yellowish, sticky residue that would be too uncivilized for something sold in the beauty department. So would A. maculata work? Probably, since the inner leaf gel is mostly just water in all species, and the supermarket bottles are mostly just water too. Then again, it is possible that it has some sort of compound in it that might actually irritate your skin. Depending on how much of a gambler you are (and how much extra A. maculata you have laying around) it may be worth a shot. Then again, I'm not even remotely a doctor, so maybe I'm not the best person to be listening to!

Some species of Aloes do indeed bleed red. Aloe vera is not one of them. Also, to quote Brad in this thread, "Aloe vera contains two kinds of 'sap' that are used medicinally. The thick yellow sap that comes from the inner lining of the leaf is called Aloe latex, and contains aloin, a powerful laxative. It flows for a little while after cutting a leaf, and can be scraped off the leaf epidermis. It is also called Aloe juice. The laxative effect of aloin is primary reason why the desert Bedouin people of Arabia cultivated Aloe vera. It has been in cultivation so long that there is no known natural population of the plant. The second kind of sap is called Aloe gel, and is contained in clear tissue of the inner leaf. This is the part of the plant that is soothing to skin. Aloe gel and Aloe latex are two different things. Aloin was used in various products until 2003, when the FDA banned its use in over the counter products because it may be carcinogenic. Again, Aloes contain two different kinds of 'sap', aloe latex and aloe gel, and these contain different compounds that are used in different ways."

Yep, I'm same way as malfleur, burning sensation and rash. Yuck. That's with just an aloe lotion, I'm afraid to even get close to the real stuff.