I'm getting better with my color sense so I'm starting to get braver.
I've been a digital scrapbooker for years. This helped me a TON. Scrapbooking has much less investment (time wise) involved in the finished product so it's been a wonderful medium to develop my color expression. Art journaling would be a great way to 'practice' too. In a way I've found that working in a couple different art mediums really strengthens both. I would encourage you to experiment in ways that help you expand and develop.