[[quoteright:350:[[WesternAnimation/AvatarTheLastAirbender http://static.tvtropes.org/pmwiki/pub/images/katara05.jpg]]]]
[[caption-width-right:350:[[ColorCodedElements It even matches her outfit]]. [[ElementalEyeColors And her eyes!]]]]

->'''Dean:''' Everyone ''knows'' the sea is blue. [[CommonKnowledge Ask anyone.]]\\
'''Ridcully:''' That's right. However, while everyone ''knows'' the sea is blue, [[RealityIsUnrealistic what everyone usually sees]] is a sea that's grey, or dark green. Not ''this'' colour. This is virulent!
-->-- ''Discworld/TheScienceOfDiscworld'', Creator/TerryPratchett, Ian Stewart and Jack Cohen.

In RealLife, you probably would have misgivings about drinking a glass of some [[color:blue:blue]] substance that presumably is clean [[color:blue:water]], but in drawn media this is just the way it looks (unless it's [[CoolClearWater unsafe for consumption]]). It's not just large enough bodies of [[color:blue:water]] to show its inherent [[color:blue:blue]] color (see below); someone might as well have spilled dye into the tap [[color:blue:water]], and even tears are not exempt. It's just easier to animate it this way, and [[RuleOfPerception easier for the audience to see]].

This {{trope}} is near universal in WesternAnimation. ComicBooks and {{Anime}} are more varied in this respect, and may even feature both solid blue and colorless, transparent blue water in the same art style. Generally, only older or cartoon-styled VideoGames feature blue water.

It should be noted that water [[TruthInTelevision does in fact]] have an ''extremely'' faint inherent blue tint in RealLife; the color just isn't noticeable unless you're looking through a great deal of it. Check Wiki/TheOtherWiki for [[http://en.wikipedia.org/wiki/Color_of_water more info.]] Though in cultural/linguistic terms the association of the water with the color blue is not OlderThanDirt per se; the Greeks of Homer's day had no word for blue in their vocabulary, so the sea was called 'wine dark'.

The color of the ''ocean'' varies, mostly depending on how close you are to shore (where it's often greenish due to dirt). In the deep ocean, it can genuinely appear a rich navy blue.

Also, some household chemicals are specifically dyed blue to discourage people from drinking them. Blue is most likely used because very few drinks are colored this way.

Aversions include tinging it white instead, or going the whole way and animating it as a distortion of the light. If water is deliberately not blue, however, chances are it's GrimyWater. Any shade of blue fits this trope, though. Compare FireIsRed and WindIsGreen.