If you want to show the player that a deal is on for example right now you have the “MOST POPULAR” or “BEST OFFER” label you could instead have a prompt when the user joins telling them that an offer is available. On some games I see Guis that show when I join the game saying there is an offer on coins or something along those lines. The style of the Gui is great however so keep it in its current form.
Like others have replied before, the grey one is much more easier on the eyes.
To add on to this, I think it would be a good idea to change up the text a bit on the buttons by adding a faint text stroke transparency, maybe
0.8, so you won’t have to look real close to see what the text says on the buttons.
On a final note, I think you should change the text of “Shop” above the cart icon to white.
Edit: You should also place the MOST POPULAR! and BEST OFFER! tags a bit more upwards so it would look cleaner, and going off of what @Dandystan said, I also think you could perhaps add a small background behind them or place them above each button.
Yeah transparency may help. Did you see his newest version of the coloured one? it seems that one is nice and on level with the grey one.
I think the numbers that shows how many Golds/Gems you get and have should not be centered. Maybe make it align from the left instead? (idk the proper word for that lol)
Also, the buy buttons can have different colors; darker yellow for golds and darker green for gems, perhaps?
Overall, cool design! I like it
The grey version looks a lot better imo. Adding a script to automatically add commas to the currency amounts at the bottom would look nice. Or a shortened version. Example: 2,500 would be 2.5k.