Yes, it is better to ask first to see if someone really wants a quilt.
For example: My aunt called my Mother to tell her she makes everyone in the family a 50th anniversary wall hanging. My mother thanked her for her generosity but told her she had no wall space to hang it so please don't make one for her.
It is important to choose your words carefully when asking a person about making them a quilt. I show them several patterns that I have saved in a folder on my computer and let them pick the style that they like. (some like modern, some traditional) I let them know the size of the quilt right away so there is no surprise when they receive it. If they ask for a larger quilt size, I let them know that I only quilt throw size quilts and larger one must be sent out to be quilted at their expense. My mother opted to send her quilt to a long arm quilter and loved choosing the quilt designs for the bed quilt I made her. As for color choices, I think this is the most important question you can ask before making a quilt for someone. If possible let the person go with you to pick from your stash or fabric store. For example: My daughter wanted a Christmas quilt. I took her to choose the fabric. I would never have come up with the colors she picked. End result...fun time shopping with her and she Loves her quilt.
There are times you want to surprise someone with a quilt, so you may have to snoop and find out fav. colors,etc.
Hope this helps you in the future!