If you look under the map on the left side you can see a key explaining what sort of diplomatic relation the different colors indicate. You can read more about them in the Galactopedia. The common ones are green (Free Trade Agreement), orange (Trade Sanctions), and red (War) - besides grey, obviously. =P
The numbers you circled indicate the volume of trade shared between your two empires. (I believe this is measured by the value of the goods, e.g. in credits, but it could be raw volume of materials) A large volume of trade with another empire will give you a slight boost in relations with them. If you enter into a Free Trade Agreement or Mutual Defense Pact with another empire, you earn bonus credits based on that volume of trade.
The Distant Worlds sale made my purchase possible. Thank you!
Oh so the number is trade amount, cool thanks. I know what the alliance colors mean I'm talking about how each empires name such as "Ancient Guardians" has a colored bar of various lengths behind it. The bar being their races main color, but the bar is a different size for each person.
Ah. I'm not 100% sure what the bar is, but I know it generally represents the strength of that faction. I'm not sure if it's based on military strength, strategic value, population, or an amalgamation of several things, but it's basically a quick measurement of that empire's power. See the Comparison screen for more detailed info.
The Distant Worlds sale made my purchase possible. Thank you!