I rarely see dark skin single eyelid Cantonese types. Doesn't matter their skin color, most Cantos have deep-set eyes and double eyelids, and you'll only find a few single-eyelid Cantos in large metropolitan areas of the Pearl River Delta like Guangzhou, Shenzhen, and Hong Kong, where mixtures with Central and North Chinese are more common. And you can trust my observations cause I have many friends and acquaintances from Guangdong and Guangxi.

Most Cantos (especially the ones from Western GD and GX) are of gracile or lanky body types with larger eyes and larger mouth shapes, very similar to Tai-Kradai minorities and SE Asians. And their skin color is mostly of medium complexion, neither too pale nor too dark. Overall they're quite good-looking, definitely above average in China.

And I rarely see stocky types in GD and GX. IMHO stocky types are more common in Central and North China. According to statistics published by the national health institute of China, GD and GX are listed amongst the thinnest regions of China, hence they aren't stocky at all. North Chinese are overall much stockier than GD and GX people, and this is due to several factors including climate, diet, and genetics. 

Cantonese having a substantial Tai-Kradai substratum is true though, and has already been proven by several Chinese linguists, most notably Li Jinfang.