I have a problem reading the commodities screen. I have no idea what those stacks of icons mean without reading your explanation.
My suggestion:
- Subtly split the rows of items into two colums, basically allign what you already have along the arrow at vertical axis
- On the left have what the planet has and needs.
- On the right show what the player has in its inventory.
- Green means: planet's = good price to buy. player's = being used by fleet.
- Red means its missing. If its a planet = you profit more by selling to them, if its you means you're missing that to work (red crew=you need more crew).
- Yellow means illegal or modified price. Usually contraband or oversupplied/demanded item.
- The arrow doesn't mean anything and could go away.
So in the above picture i edited with paint.net:
- Metals - you can buy them for cheap (green) to sell elsewhere.
- Hand Weapons - most of it is cheap, some is normal price.
- Food - the player has some food and needs more (lets assume its needed like supplies). Buy some from the planet so your fleet can function.
- Supplies - normal prices on both ends.
- Crew - the planet is selling discounted crew and crew at normal prices. The player is using all of the crew and selling it means putting ships under strength.
- Organics - cheap organics on the planet.
- Domestic goods - the planet needs these badly, sell all of yours for phat profits now.
- Fuel - planet has some fuel and needs more - good profit from this.
Hope its clear. I'd wager the colours could change again - my best idea is to make the colours a trading skill learning in the character advancement screen where invensting in a skill would give those coloured outlines telling the player what's good to buy or sell ("green = do it, red = don't do it" kind of thing)