The kit is very easy to use. It has detailed instructions on how to dye.
The cobalt blue colour looks very vibrant in itself. I had left the dye on for 36+ hours by mistake. I had used the prewash fixative before that. I had used the DYFIX in first wash and there was minimal bleed in the second wash. Hopefully the dye will stay on for longer time.
Might edit the review later after wearing the tshirt and checking if it bleeds due to sweating.