Looking great
That blue tint is the IBL working. Image Based Lighting is lighting information taken from a cubemap image and used on a model for realistic rendering. The one on the render panel is the image you are currently using. It can be changed to any cubemap simply by dragging another cubemap image to the texture box. IBL images are best blurred for the best effect otherwise they are a reflection image.
What it does on a 360 degrees radius is light the model with a colour from the cubemap blending it to the sky colour, side & ground colours. hence blue for the sky. Its a better form of global illumination like hemispherical lighting and is a technique all the modern renderers use to get the AAA quality as it saves time for the artist having to blend all the textures and lights correctly.
Any surface facing the bottom will end up with a green or brown colour. By having 2 different lighting colours from top & bottom; it creates depth and blends every asset together. For example: on the render panel, turn the IBL Mix slider down to reduce the overall scene IBL intensity. If set to 0, it will have a flat single ambient colour and a light colour from the directional light, this is what advanced looked like. If you type in 1000 though, you will instantly see the effect create more depth and blending in your level.
From your shot, the skybox you have won't match the default IBL image, as it has a more golden sky colour. Which means the buildings should have a more golden colour. Which your objects should be showing to make them believable in that environment.
Each material can be tweaked to take on more or less mix of the IBL, as some surfaces do not need it. As for your buildings, on the material editor, switch to the IBl tab(one to the right of the texture assignment), and reduce the mix to around 700. This will make them blend better.
If you send me that skybox, i will make an IBL image for you or try the ATI cubemap tool on the asset store. Its not the easiest tool to use, but it gets the blurring job done
Hope this helps explain a few things.