one side of the tree is still green but the North side and both east and west sides are yellowing with this rusty residue on them.....

This sounds like a case of transplant shock which in part may have been caused by putting in an oversized tree. I doubt all the roots originally grown came with the tree and it may take one or more years for the tree to adjust and compensate. At least, if the growth isn't scorched looking and is only dwarfed, it sounds like the care you are giving is adequate. I think you just need to wait this out. You know, red oaks are very fast growing. You probably could have opted for a smaller tree and gotten the results you wanted for screening rather quickly.

Sorry, I thought the problem was more intensity that redness. To address too much red: First, run a trial with your top coat of finish. This often tones things down. To kill red, you apply green (its color opposite). In the stain palette, this is usually raw umber. God knows what the stain manufacturers might call this. You might ask the paint store to give you a squirt or two of raw umber UTC in a jar you've taken in. One of the stains I use can be a shocking cordovan color on some woods. A treatment with brown glaze really settles it down. In short, you are going to have to run some test panels, through to completion, to find the best solution.

The sad thing was that 78" of rain (as I am sure you know) can be just as damaging for garden plants as a year with 18 or 20" of rain. Aside from the garden and farming issues, our county courthouse flooded (and it wasn't the only place that flooded, just the most well-known) on a May 2015 day when we got about 12" of rain in some parts of the county (including our house) and a lot of roads were flooded, washed out, wiped away, etc. I think all of the roads had been repaired and reopened.....and last week's flooding got some of them and now they are washed out, destroyed and closed again, and unlikely to be repaired until after the spring's storm season has passed at the very earlirst. While we think of a rainy season as being a good year, it still can do a lot of damage. Sadly, that was not even the first day my garden has been subjected to 12" in one day, but it was the first time that's happened since April of 2009. It is aggravating to have a river of rainwater running across your property, but no less aggravating than drought or wildfire. Here in Oklahoma, the land of extreme weather (a title Texas could claim as well), we always seem to go from feast to famine to feast in terms of rainfall. Last year's rainfall was epic, and I hope we don't have that sort of year again this year. It is starting to look like April 2016 bears too much of a resemblance to 2015 in that respect. Scale seems prone to move in and attack stressed trees. Being recently transplanted in the last couple of years and then being blasted by too much water could have been the stress that led to scale attacking your trees. If they were my trees, even after I'd eliminated the scale this year, I'd probably spray them with a dormant oil next winter during the dormant season just to prevent any surviving scale from reappearing next spring. It's better to be safe than sorry. I was looking at flood damage along the Red River yesterday, including formerly thriving winter wheat crops buried under silt and floodwaters, and thinking to myself "here we go again". We almost bought land adjacent to the river and talked ourselves out of it, instead buying close to the river but on high enough ground that our house would be very unlikely to flood. Every time the river floods, I am grateful we made that decision. I can handle a flooded garden and yard, but wouldn't be happy to have a flooded house, and even in last year's worst possible case flooding scenario, our house was never at risk of being flooded. Our yard and garden were buried under pond-sized puddles for weeks and weeks at a time though. As plants leaf out (or, more accurately, don't leaf out) this spring, we're learning what did or did not survive the flooding, and I am shocked at how few plants apparently died.