Kianna, for most of us here, your heatlight IS your basking light, only one heat source is required.
"basking spot' refers to a branch/perch/vine etc, directly beneath the heat source (this needs to be at the right distance (down) from the heat source, so that the temperature,
taken at the 'basking spot' is ideal for your species.
About the tail, on occasion, color change occurs according to mood/temp etc, even in places like the tail. Ive seen my chameleons tail go dark before today and have me double checking everything, imaginiong the worst, but later will be its normal green.
If your heat source is ontop and the basking spot at suitable distance, then a burn only on the tail is unlikely. It may be something to do with shedding you mention.
trying to clarify this...
Trying to understand your question the heat lamp is the fixture light i have sitting on top of his cage and his basking light is on the side of the cage clamp on to support the basking light.
Do you mean that your heat source is attached via a clamp on the side of the cage, but shining from above?