[...]Did you try a light or medium gray for the mods? [...]
I second this.
I hope Fredington thinks on this.  Even a single color of yellow would be an improvement IMO.  I love fun sets like this, and I really want to buy it.  I adore my DCS Turtle Power caps.  This is just as radical.
Mono yellow is a possibility, perhaps with the accents moved into their own kit.
However, yellow alphas and gray mods was the first color combination I tried, and I was not a fan. More importantly, it takes away the opportunity for the blue SPORTS on a yellow background novelty, which I feel is central to this set's identity.