Basic Opaque 2.5-Inch Plastic Spike *sold per spike*
Can be attached with a little bit of super glue if you scratch up the base first. Alternately you can drill small holes along the base, and sew them down.
You can NOT get neon colors with this type of spike, because the base resin is white; it will always turn out more pastel. If you want a neon color but opaque, please see the UV spikes. If you want a custom colored spike, or want it to match a hex code you will need to purchase the "custom colored opaque 2.5-inch plastic spike". If you want to get as close as possible to your special color even if it isn't neon, think about ordering the UV spikes. They have a clear base, so have an easier time of matching.