Water is Blue
Water is blue. But only slightly blue. In small amounts, the blueness is too weak, and the water is the colour of whatever is dissolved in it. For example mud and coca cola are brown. Urine can have a wide range of colours depending on the ingredients. It can even be orange.
That is one option for orange water. Dissolved urea (Edit: dissolved urochrome). Another is dissolved iron. This is what happens when iron water pipes rust.
I am sure there are other dissolved things that work equally well.
This should not be a problem for complex life. Consider the caustic soda lakes of Earth. These have shrimp and flamingoes specially adapted to live in the alkaline water. A little urea or iron is no problem if they have time to evolve.
The ocean is blue because (a) water is blue and (b) because it reflects the blue sky. If the sky is orange instead then (a) does not work because blue is opposed to orange on the colour wheel.
So all the light that comes from the sea is the reflected light. You get a dark sea.
Note you can find pictures where the sea is orange and not dark. This would happen if (b) a lot of light is reflected. However it is hard to trust the orange sea photos are not photoshopped to make the sunset look more beautiful.
In this video we see some orange in the middle of a dark sea.
That suggests some orangeness is indeed possible. And the video is harder to fake than the picture. Though there are still options to fiddle with the colour balance.
The only way to be sure is to go to the beach at sunset and see for yourself. Have fun.
Note: There is a subtle point about the difference between (A) an orange sky and (B) only orange light reaching the surface. I think during sunset (B) happens because other things are tinted orange and not just the sky. This is equivalent to the sun being orange. But it is possible there is another way for (A) to happen with a white sun.