I have a cube set the Material to be ‘Emission’, save an run the game. The object will have the color I chose but has shades. In previous version of armory the cube was (as expected) plain flat.
I believe that in the preview is not considering the lamp in the model with emission.
Another thing that the emission in the blender is “stronger” than in Armory, to get similar values you need to put larger numbers in the emission. For emission to appear is good to put a value above 10, I get a similar value between 50 to 100, with sun style light in the value 1, these settings in the cube was similar to me.
Thanks for your answer. However the behavior you describe is excatly what I do NOT expect to happen. A lamp should have no influence on an emitting object (if the emission above 1). And as mentioned in my first post, in version armory v2019.6 ($Id: a1f62c5c53fd416d5483932a490fe041c6af29f3 $) the blend file works as expected. Here’s a comparison: