The current default settings for the item guides aren't the best. They don't fit with vanilla's aesthetics and just generally stick out a lot. To solve this, and to make customization easier for people who don't want item guides/want to change them:

• Change the default non-highlighted color from aqua blue to the color used for vanilla inventory slots. Definitely keep some transparency, though.
• Change the default highlighted color from green to the color used for hovering a mouse over an inventory slot.
• Add some presets in the config screen to make customization easier (should spin this off into another issue).

From this Discord thread: https://discord.com/channels/1061675558347489343/1283841463913807885/1283841463913807885