Generally speaking, butterflies, especially two butterflies from fly with me, often symbolize love and romance. In addition, the butterfly is a beautiful animal psychologically, but it evolved from an ugly caterpillar. From the ugliness in the caterpillar period, the biting of flowers and leaves, the winding crawling, to the beauty in the butterfly period, drinking wind and eating dew, flying freely, also symbolizes the hope of getting rid of secular constraints and paying attention to spiritual freedom. However, butterflies are fragile while sucking nectar and not touching worldly things. Just like the fantasy love in a girl's heart, beauty and purity are often not true and strong.
As for the symbolic meaning of the butterfly in your dream, I think you should ask yourself. But there are two butterflies in the dream, and one of them is dim, which seems to have practical significance. In reality, among butterflies of the same species, males are often brighter and females are darker, but when you want to catch them, you are a little scared. Is it also a symbol? You are looking forward to a beautiful, illusory and out-of-touch love, but your heart doesn't believe in this pure love, so you want it and are afraid of disillusionment. Deep down, you have understood the nothingness of this pure love, so you will have "slight sadness"
This dream has given me a good feeling, delicate feelings, and I am more eager for spiritual freedom and nobility.