By default, your scene will be lit only from the environment, which however does not include actual lights, as if it was a cloudy day. If most of the sky is blue, your object will be blue.
You can start by adding a
DirectionalLight, which acts like a sun, and will light up your scene with white much better. Then, if you want the sky to have less influence over the scene overall, you can tune it down by reducing the
Sky Contribution property, in your
default_env.tres resource file. You can also change sky color, or override the whole environment in that scene by adding a
WorldEnvironment node to your scene with a custom