I'd first check your print file colour profile as RGB and CMYK can print differently. It could also be worth checking if the listing images are in CMYK or RGB as again, this can sometimes alter the colours on different screens. However, the best option is to go to PrintShrimp and work with them to diagnose the issue. If it's a fault their end they might be able to reprint for free.

I love that your doing this as part of your course. Don't worry about quantity, just focus on producing illustrations that you love. Obviously there is a balance, but i think your originality and a bit of marketing on the right platform will be key to your success. You've got a great opportunity to film the process, which customers will like. You could look at offering a limited number of prints per illustration to make them feel more premium. I'd also think about taking one illustration and finding away to create multiple products from it. It could be printed on to different products like posters or a t-shirt OR can you take small elements of your illustration/style and create a mini series with it. Customers could buy one small print or a collection of six for example – without seeing your designs I can't see if this would work, but it's all about thinking outside of the box! Good luck. Please share your shop when it's ready :)

@Daizy Wood Rowe I’ll double check the header, thank you for spotting it. And thank you for the lovely feedback xx

@Mihai Volintiriu Thank you. I always want something I can't have! 😂