Omg I agree with others, I’m late 40s and some of these gifts sound totally depressing, I’m late 40s not late 70s. As for a safe shade of blue, I hate most shades of blue. Unless you know someone’s favourite colour I’d totally avoid buying something to wear.
Your mum - obviously very hard, my in-laws love their dogs, every Christmas I always include something for the dogs, chew toys, new balls etc..this goes down well. Dose she wear wellies while walking the dogs, I’m thinking nice welly socks/liners other than that maybe a voucher for a nice restaurant she would enjoy if not I definitely ask especially if she dosnt have any things she likes personally. I made up hampers for the in-laws a couple of years ago, I put in dog toys, mug for FIL (non drinker) his favourite tea bag’s & biscuits, pair of warm socks, sudoku book & portable power bank for his phone, MIL got gin liquor which I knew she loved, gin glass, dog toys, nice chocolate & a candle. Other dog related things, I bought FIL (main dog walker) a heated gilet, he uses it when walking dogs and going to the football.
Stepmum - may be easier, dose she have a particular brand of skin care she likes, my Mum always liked a certain face cream but couldn’t always afford it so I’d buy it for Xmas & birthdays. Massage gun or voucher for deep tissue massage, new EarPods for running…
Most generic gifts I get given end up regifted or donated. I never liked vouchers when I was younger but like them now, I don’t like ones that are for a certain shop though, I prefer ones that give me an option where to shop.