Ale beers have a pale amber colour
Ale is nowadays defined as any beer made with top fermenting yeast, in contrast to lager—which is defined as any beer made with bottom fermenting yeast. But its origins are somehow different, being the definition of ale by the Encyclopedia Britannica in 1773 a fermented liquor obtained from an infusion of malt and differing only from beer in having a less proportion of hops. Thus the origin of the term ale comes from Old English alu or ealu, referring to a totally unhopped beverage, in contrast to the the continental hopped bere that arrived to the UK in the 15th century.
American Pale Ale (APA) is a refreshing and hoppy, ale, with enough supporting malts to guarantee drinkability. ABV ranges between 4.5 and 6,2 ABV, and bitterness goes from 30 to 50 IBUs. Hops can range from traditional to modern American hops. Appearance is pale to light amber, and flavours and aromas are hoppy with floral and fruity notes. It is lighter and cleaner than English Pale Ales, and more accesible that modern day American IPA's.
Amber Ale is quite related with American Pale Ales, even though they have a different malt ballance. Its appearance is amber to coppery brown, with a moderate hoppy aroma with fruity characteristics from american hops, and also high maltiness. Flavor is moderately to highly hopped, with floral notes and a lot of malty sweetness. Finish is sweet with hints of hoppy bitterness. In comparison, they're maltier than American Pale Ales, and less hoppier and alcoholic than Red IPA's.
Barley Wine is an American reinterpretation of classic English Barley Wine. Color ranges from light amber to medium copper, and aromas are quite hoppy, with floral notes of American hops. Taste is ballance between malt sweetness and hop bitterness, but the ballance is always towards bitter, with a strong alcoholic character. It is less hoppy and sweeter than an Imperial IPA.
English Brown Ales are itself a very varied category, ranging from lighter and hoppy to darker and more caramel and roasted beers. Their American counterparts tend to be more hoppy. Malts used are caramel and chocolate, and hops varieties are mostly English. It is a more malty style than British Bitters, and less roast than English Porters, and with less sweetness than London Brown Ales.
ESB is the acronym of Extra Strong Bitter or Extra Special Bitter—ESB is a registered trademark in UK by Fuller's Brewery. Although in the UK, it describes a very unique kind of beer, in the US, it describes a more generic malty, bitter, reddish British ale.
Flavour ranges from balanced to bitter, but always pretty drinkable. Hop aroma is moderately high to moderately low, and flavour is based in its bready, biscuity malt profile. Can be compared with an American Pale Ale, but with more malt flavour and different hop character.
Fruit beer is a broad category, that holds any ale or lager made in combination with one of many fruits—being spices, herbs or vegetables not considered as fruits for this style. Appearance should reflect the fruit at some instance, and flavour should be associated with that fruit.
Old ale is an ale with more ABV than standard beers, but not as alcoholic as Barleywine. Its appearance ranges from light amber to very dark brown, and aromas are malty with combination of dried fruits, caramel, toffee and other malty aromas. Taste is also very malty, and sometimes also hopped, with a dry to sweet finish. It is usually an aged beer, and it generally has more barrel qualities, in contrast with Barleywine.
Scotch Ale is a very sweet and malty style, with a copper to dark appearance. Malt is prominent in the beer, giving aromas a strong malty character, with caramel and sometimes smoked hints. Flavors tend to have a lot of caramel and some smoked roastness, with a sweet to dry finish. It shares some similarities with English Barleywine.
American Strong Ale
American Strong Ale is a catch all style that includes all American Variation as English Ales as well as other reinterpretations with high content of both malts and hops, like some Imperial IPA's, some Amber Ales, or many East Coast IPA's. They are not as strong as American Barleywine, and more malty than a Imperial IPA.
Blond Ale is a slightly stronger version of a golden ale, with some yeast complexity. Its Belgian version is related with Dubbel or Tripel, while the British version is more hoppy and refreshing, almost as an American Pale Ale, while the American and Canadian versions are less hopped.