Alagoas's represents the region's original three cities: Penedo (tower), Porto Calvo (rocks) and Alagoas (a.k.a. Marechal Deodoro, fish), the three fish representing its three main lagoons. I kept the fish, and the star from the crest.
Chevrons are somewhat of a recurring element in my state flags; since they're half of a rhombus, I find them a nice alternative to one as a reference to the national flag.
The first of these flags for Amazonas is a simplified version of its , which depicts the confluence of the into the Amazon river, and some interlaced arrows and feathers (as well as a Phrygian cap and star, not included in this flag). The third is based on the state's 1897 military flag, while #2 and #4 are versions of both using the current flag's colors.
The flag of Ceará isn't alone in taking inspiration from the national flag, but is in using the exact same base design of green background and yellow rhombus, rendering it confusingly similar. The Arizona-style rays on this redesign represent Ceará's purported etymology "mother of light" as well as the Mucuripe lighthouse depicted on the . The seven stars (one for each of the state's mesoregions) and bird are also from the arms.
The main element of these designs for Espírito Santo is a triangle and three stars (in addition to a large one in #3). They represent the Christian , often depicted by in the shape of a downward-pointing triangle, since the state is named after the third of the three Trinitarian persons, the (hence the third star, at the bottom, being colored differently). The stars also reference the three stars surrounding the , which represent the three bordering states. #4 hints at the , since Espírito Santo is represented on the national flag by the constellation's (roughly) central and smallest star, Epsilon Crucis.
The first design replaces the green square with the kite shape of the district's , which symbolizes the pillars of the presidential palace. The quartering in the second and third is based on the arms as well. #3 uses the national flag's rhombus and circle (if there is any type of entity for which it makes sense to have a nod to its parent country's flag, it's probably a capital city, and especially a one).
Goiás, Piauí and Sergipe
Sergipe's and Goiás's flags are very similar, the number of stripes being the only major difference. The first of these redesigns for Goiás use a simplified version of , depicting a comet and a diamond. The second is more true to the current flag, only keeping the arms' heart shape (which represents Goiás as the geographical "heart" of Brazil). Those for Sergipe use a hot air balloon, the main element of , replacing the "Porvir" motto with the five stars from the current flag.
Another flag using the same Stars and Stripes-like style in the same colors is Piauí's, which has a single star and a date written below it in the canton. Again based on the , I used a fish as the main charge, here representing the animal being the origin of the name "Piauí". #1 reduces the number of stripes to seven after the seven blue stripes of the arms (which represent the tributaries of the ); #2 is a quadricolor based on the colors of the arms.
Since making these designs I've come to really like the current flag of Mato Grosso: as far as variations on the national flag go, it does a great job at being distinctive despite having the same basic design and color scheme, due to its color switch and single large star. It also has history, only being a few months younger than the original version of the Brazilian flag itself. Anyway, these designs take inspiration from the , which depicts the used on both redesigns. The first combines the current flag's diamond with the arms' colors and gold mointain (the similarity to Henrique O'Voador's design is purely coincidental); the second replaces it with a fimbriated chevron, keeping the current flag's colors.
Of the symbols on the state's , the crossed pickaxes seem appropriate to use, given the state's name ("General Mines"). The white star and sky blue lines are also from there; the star may here symbolize statehood as well as liberty (replacing the Latin motto which means "freedom, albeit late").
The inscription "Nego" means "I deny", referring to the state's opposition to the presidential inauguration of during the . I replaced it by a saltire, serving as a less literal . The shapes in the four quarters of the first design are from the and represent sugarcanes; the second instead uses the star from the .
Paraná's current flag is quite good (despite the inclusion of the state name); the main changes I made are replacing the branches by blue cottises, and changing the constellation Crux to Triangulae Australis (which includes on the national flag).
Rio de Janeiro
The first flag is based on an unsubmitted Reddit contest entry from May 2017; it combines the state's blue and white quartering with the saltire from the . It is charged with the central emblem of the (a blue disc with white border, band and star, reminiscent of the national flag's celestial globe) without the inscriptions. #2 through #4 display the eagle that carries the globe on the coat of arms, using the stylized depiction as used on government websites.
Rio Grande do Norte
This flag keeps the current one's central shield, but replaces the coat of arms with a single white star.
Rio Grande do Sul
#1 is a simplified version of the central part of current flag's colors: a rhombus between two pillars, charged with a sword and Phrygian cap. #2 and #3 use the current diagonal triband with a simplified central emblem; #3 is a twin of my design for the similarly named (though located on the opposite end of the country) Rio Grande do Norte, featuring a single white star., in the
Freely based on the Rondônia, which has a pointed diamond shape representing the top view of a fort (much like the charge on the flag of Amapá) and contains a white star with a yellow and green trail.of
The current flag's weirdly placed red line represents the Equator crossing through the southern part of the state. I reoriented the blue-white-green background to match, moving the star to the upper left (which may also symbolize Roraima's northwesterly location in Brazil). The second flag takes the heron from the .
These designs simplify the state's , which is currently entirely included on the flag, keeping the crossed anchor and key (which represent the state's safe and strategic location respectively) and a star. The last two versions instead display a , symbol of the state's namesake , who is said to have broken the torturing wheel she was to be executed on by touching it.
Originally a failed proposal for the whole country in 1888, this flag stayed in use in São Paulo until its adoption as state flag over half a century later. The first of my designs uses a rhombus (and the second a chevron) as a more symbolic reference to Brazil than a map, charged with the sword, star and laurel and oak branches from the . The third uses the , which is depicted on the national flag, where its brightest star represents São Paulo, as well as on the current state flag by the four stars.
Nothing wrong with Tocantins's current flag, but its works quite well as a flag too. I changed the white part to serve as a border for the blue and gold chevrons.