Some advice for a Newbie Quilter!
 

Black, white and red colors are classics. If you are short on red, why not treat yourself and buy some that will be enough to make this quilt.

Adding in shades of gray would work well with red/white/black. Another point is that your red, white and black fabric don't have to be all the same----you can buy a few other similar but different reds, whites and blacks so each block has the same color theme but in different fabrics.

purple, blue, green, pink, yellow...all deepest shade...would work.

Make it a controlled scrappy by adding additional fabric in the same colors. You could do each block using the same fabric of each color or you could mix it up throughout. Either way I think it would make a gorgeous quilt. Black white and red is one of my favorite color combinations.

Or make a smaller quilt using what you have.

Any colors that have sharp contrast from each other would work. I would make blocks using different colors in some blocks, try to use one constant, maybe all have the same background fabric. I wouldn't worry about having all the same colors. You can make one long table runner if you want to use the fabric you have for the blocks to be all the same.

You could use any color combinations just make the black and grey in the same colors - one dark and one light. Such as blues with red, green, yellow where the red is. You can also make them all different giving it a scrappy look. This was the biggest eye opener for me. Realizing that I can choose the colors I want. It can give the quilt a whole different look with different colors. I like that block. Can't wait to see what you do with it.