Back in the days when Scythe Harvesting mods were new, they had a rather... unique "bug" in that flowers harvested in this manner were reset to the default color that appears if you were to look at them through an item spawner mod, or in the springobjects png file. This was ultimately very helpful, if not necessarily intended, because the vanilla flowers can take up upwards of 12+ inventory spaces between color + quality differences, which can lead to one's inventory filling up quite rapidly - not to mention without repeated re-harvesting or outright cheating, completing bundles with flowers can be quite tedious as you need X of all one color. Now, I'm not asking for this feature bug to be restored; rather, I just want a mod that has the functionality to unify flower colors, whether with a button press or by some other means that would work for both vanilla and modded flowers alike (I use Mizu's Flowers and Farmer to Florist for JsonAssets). - Drowning in flowers Resolved!
Although not exactly what you are looking for, Flower Color Picker can let you (individually) set the color of the flowers while they are still growing. If it's your first harvest, you can use whichever you picked first and set the rest to match. And it does work with modded crops too.