I'll say from the start that I think the Florida Marlins had the best uniforms in baseball, hands down. I also think the Miami Marlins have the worst. I'll take a look at the decisions made on the logo, lettering, and color choices to explain why these new uniforms fall short of their predecessors.
Let's start with the new hat. The first thing I personally noticed, and I've seen a few others make the same comment, is that the logo looks huge on the hat. The reason for this appearance is the new shape of the logo in relation to our previous logo. The F logo was smaller on the bottom than it was on top, measuring 1 5/8" along the base of the F and 2 7/8" from the bill of the fish to the top left corner of the F. Without a new hat next to me, I can't know the dimensions for sure, but I can estimate that the base of the M measures at least 3" while the top of the logo appears to be at least 1 7/8" wide. This overall greater width give the appearance that the logo is drastically over sized even if the overall width of an average hat is about 6", or twice the width of the logo.
Now, let's look at the logo itself. After staring at the logo for a time, I have convinced myself that I wouldn't mind the logo if the M were a solid white, even if we did ditch the teal. The reason is the proportion of the piping to the primary color of the M. If you take a look at your Florida Marlins hat, the silver piping around the F is approximately 20% the width of the vertical stroke of the F. This helps to create a clear hierarchy of a dominant black F with a minor silver outline, in other words the silver outline helped to accentuate the black F, not compete with it. Our new logo's piping appears to be at least 75% of the white M on the hat. This creates a tension between what should be the dominant white M and the complimentary piping, instead of accentuating the M, the piping competes with it for attention and causes an uneasiness for the viewer. Another problem with the piping is that it is not a single color. When you change colors in an outline, it creates and incongruity that must be cleverly addressed to sufficiently overcome its drawbacks. That didn't happen here, instead the colors change abruptly at certain changes in direction around the M. The orange and blue are dark enough to work well as border colors, but the yellow is very light and it fails to cap the M, the viewer's eyes can easily escape the top of the M because it doesn't have a strong graphic stop the way the other sides of the M do. A completely yellow boundary would have worked, or a completely dark boundary would work too, but when some of the colors have a dark hue and some have a light hue, visual containment becomes an issue.
Now, let's take a look at the jerseys and the lettering. In my mind the black jersey best illustrates the missteps made in this uniform's design. At first glance, and again on second, third, and one-hundredth glance, the jersey front looks "busy." Again, this issue comes from the piping around the letters. The black and white borders are similar to the previous uniforms in that they completely surround the letters, but the fact that the jersey color is one of the border colors adds to the "busy" look. The big difference however comes in the orange "border." Here the orange is only used on the undersides of the letters, again creating and incongruity that causes visual uneasiness due to the lack of resolution of the piping. Here we are trying to incorporate three colors, two of which are complimentary and two of which are analogous, as well as black and white; the result is an unbalanced and busy line of text that feels like it is trying to be different for the sake of being different rather than for an enhanced design. The second issue with the uniform deals with the use of the M logo on the right breast to begin the spelling of Miami. Because the colors are not uniform across the jersey, a visual imbalance is created.
The color choices also contribute to the visual uneasiness apparent in the overall design. The beauty of our previous logo was it's chromatic simplicity, one color, black, and silver. The dark hue of the teal fit very well with the black lettering and the silver piping was a nice touch to avoid a mundane white border. We now have three main colors: orange, yellow, and blue. Orange and blue are complimentary colors and generally go well together, and orange and yellow are analogous colors, that can go well together although it's trickier. The problem comes from the hues of each color. The blue and orange appear to be relatively dark hues making them blend nicely on the darker uniforms and contrast well on the light uniforms. The yellow is a light hue, which on its own is not a problem, but it struggles to play nice with the darker orange and blue hues in these uniforms. The yellow is reacting to the background of the uniform differently than the orange and blue are so the viewer retains an unsettling feeling as they go from colors that blend to colors that contrast.
The biggest problem I have with the uniform change is that we already had such great uniforms. I had people who were not Marlins fans tell me that the Marlins had the best hat in baseball, one that people could wear even if they were not Marlins fans. We had a sensible color scheme and clean, classic uniforms. The classic white pinstripes at home, and clean grey road uniforms made for uniforms that had all the elements of the long lasting classics found in the Dodger and Yankee organizations. Our current uniforms fail to live up to that clean and classic benchmark set by the Florida Marlins. Instead they feel trendy and dated already. I can't see these uniforms surviving generations of Marlins fans they way the uniforms of some of the most storied franchises in baseball have, and that's the downfall.