Crabbe and Goyle might be a bit confused. They are used to following Draco and might not understand why he would do something so out of the ordinary. But they would still stand by him, mostly because they are loyal to Draco more than they care about his hair color.
Blaise Zabini might be amused. He would probably tease Draco a bit at first, but then support him because Blaise is often portrayed as someone who is confident and not overly bound by convention. He might even give Draco some tips on how to make the hair color look even better.
Others might be a bit shocked at first. But after getting used to it, they could come around. For example, they might initially tease him a little but then realize it's just Harry being Harry and trying something new.
Dyeing hair depended on the individual's color needs. If one wanted to achieve a more transparent color, especially if the hair color was light, one usually needed to first rinse the hair to wash off the black dye in the hair before dyeing it. Blowing hair could make the color of the dyed hair look better, but at the same time, it would further damage the hair quality, making the color easier to fade after dyeing. If you are not sensitive to color and do not want to dye your hair frequently, you can choose not to rinse your hair. Hair that was not dyed could protect the hair quality, but the effect of dyeing hair might not be as obvious as dyeing hair after being dyed. Therefore, whether dyeing hair was good or not depended on the individual's balance between color effect and hair quality protection.
Harry might be initially skeptical. He has a history with Draco, so he'd be worried for Ginny. But over time, if he sees how happy Draco makes Ginny, he could come around. Hermione would probably be more open - minded. She'd look at Draco's character development and judge based on that. Ron, on the other hand, would be the most difficult. He'd be very protective of Ginny and would likely grumble a lot at first.
Draco's Slytherin friends would be quite shocked. Some might shun him, thinking he's betraying the Slytherin ideals. However, a few might see the advantage of having a connection to Harry Potter. For example, if there are any threats to Slytherin as a whole, Harry's influence could be useful. So there would be a split in how Draco's Slytherin friends react.
Hermione could also be very hurt. Her hair is part of her identity, and having Draco, who she already has a strained relationship with, do something so cruel would cut deep. She might go to her friends, Harry and Ron, for support. They would likely be just as angry as she is and plot some sort of revenge against Draco and his Slytherin friends.
The other Gryffindors would likely be divided. Some would be outraged, thinking that Hermione has betrayed the house by getting involved with a Slytherin, especially Draco Malfoy. However, others might be more understanding and see that love can cross house boundaries. In Slytherin, Draco's friends would also have mixed reactions. Some would be proud that Draco has managed to get Hermione pregnant, seeing it as a sort of conquest, while others might worry about the implications for their standing in the wizarding world.
Hermione's friends from Gryffindor would be a mix of disbelief and concern. Neville, for example, would be worried that Draco might be using Hermione in some way. Luna would be more accepting, seeing it as a unique and interesting relationship that defies the norms of the wizarding world. As for Draco's friends from Slytherin, they would also be shocked. Some might see it as a betrayal of Slytherin values, while others might be intrigued by the power dynamics at play between a Muggle - born witch and a pure - blood wizard.
His Slytherin friends might be initially shocked. Some could mock him for wanting something so 'cute' and un - Slytherin - like. But others might secretly support him, like maybe Pansy could see how much it means to him and help him keep it a secret from those who would oppose.
Harry's friends would be extremely confused at first. Hermione might suspect something is wrong right away and start investigating. Ron, on the other hand, might be more straightforward and just think Harry has gone a bit strange. The Gryffindors might be suspicious of 'Harry' (really Draco) acting differently. For Draco's friends, they would also notice the change. Crabbe and Goyle might not be smart enough to figure it out immediately, but Pansy might sense that something is off with 'Draco' (really Harry).
Harry and Ron would probably be shocked at first. Ron, especially, might have a hard time accepting it because of his past relationship with Hermione. But eventually, they would come around because they care about Hermione. Ginny would likely be more open - minded and try to be supportive. Other friends from Hogwarts might also be divided, some might be against it because of the long - standing rivalry between the Gryffindors and Slytherins, while others would see it as a chance for unity in the wizarding world.