public async Task <ActionResult> SaveCrayon(CrayonViewModel model)
        {
            var instrument = await context.Crayons.FirstOrDefaultAsync(c => c.Id == model.Id);

            if (instrument == null)
            {
                instrument = new Crayon
                {
                    Id        = model.Id,
                    HTMLColor = model.Color
                };
                context.Crayons.Add(instrument);
            }
            else
            {
                instrument.HTMLColor = model.Color;
            }

            var changes = await context.SaveChangesAsync();

            var ret = mapper.Map <CrayonViewModel>(instrument);

            return(RedirectToAction("Crayon", new { CrayonId = ret.Id }));
        }