Combine 1 cup granulated sugar and 1 cup water in a medium saucepot. Bring to a boil over medium-high heat, stirring to dissolve the sugar. Add 1 thinly sliced blood orange and reduce heat to medium-low. Continue to simmer for 10 minutes or until the rind is soft. Remove from heat and drain the liquid. Lay the orange slices on a wire rack and let cool overnight.

Preheat oven to 400 degrees F. Line a baking sheet with parchment paper.

Make the pate choux for the eclairs. Combine ¼ cup butter with ⅔ cup water in a medium saucepot over medium-high heat. Bring to a rolling boil and reduce heat to low. Add ½ cup all-purpose flour, stirring the mixture with a wooden spoon until a dough forms. Take the mixture off the heat and let cool slightly, about 2-3 minutes. Slowly add the whisked eggs a little at a time to the dough, stirring well to make a smooth paste. Transfer the dough to a piping bag and pipe 12 lines 6-inches long on the prepared baking sheet pan. The lines should be about ½-inch thick and be about 1 inch apart from one another. Bake the pate choux in the oven at 400 degrees F for 10 minutes. Reduce the oven to 325 degrees F and continue to bake another 20 minutes or until golden brown.

Remove the eclairs from the oven and transfer them to a wire rack. Let cool completely.

Make the orange curd. Whisk together 4 egg yolks with ¾ cup granulated sugar, ½ cup blood orange juice, and 1 tablespoon blood orange zest in a heat-safe bowl. Make a double boiler, filling a small pot halfway with water. Bring the water to a boil, reduce the heat to medium and place the bowl with the egg yolk mixture on top of the pot. The bowl should not be directly touching the water. Continue to cook the curd until thickened, about 10 minutes. As the curd begins to get thicker, start to whisk constantly. The curd is ready when it coats the back of a spoon.

Remove the orange curd from heat and transfer to a bowl. Cover with plastic wrap directly touching the curd and cool completely.

Whip 1 ½ cups heavy cream until stiff peaks form. Gently mix in 6 tablespoon of the cooled orange curd. Don't worry if the curd doesn't completely mix in, you just want to combine the two. Transfer the cream filling to a piping bag.

Mix 1 ½ cup powdered sugar with 2 tablespoon lime juice to make a thick lime glaze. Mix the remaining ½ cup powdered sugar with 1 tablespoon blood orange juice to make another glaze. The blood orange glaze will be thinner in consistency than the lime glaze. Transfer both glazes to 2 different piping bags.

Cut the eclair shells in half lengthwise. Pipe the lime juice on the top shell. Wet a finger with water and smooth out the icing.

Pipe the orange cream filling on the bottom shell. Top with the shell with the lime icing. Drizzle the blood orange icing on top to create a pretty pattern. Place the candied blood orange slices on top and finish with chopped pistachios. Serve immediately.