Your going to have to order them online but so long as that is ok you can shop from Adult Cloth Diaper.com link below for some colored but plainer designed ones.
https://www.adultclothdiaper.com/PLASTI ... stic-Pants
For some more babyish ones you can try Baby Kins.com
https://www.babykins.com/collections/ad ... stic-pants
Rearz also has a pretty wide selection
https://rearz.ca/incontinence/incontine ... ing&page=5
Just as a side note; only buy the nighttime variety if you intend to wear them in bed exclusively as they can be very uncomfortable if worn while doing much activity.