Alder is crap under dyes. You'll want to use either a tinted clear finish (lacquer or otherwise), or use a pre-stain and then a stain. The top photo looks like a brown mahogany tint, and the bottom one looks like more of a heritage-cherry.
If you want to go with a tinted spray lacquer, Behlen makes a set of them that I have had luck with. Check out https://www.shellac.net/behlen_aerosol_list.html for a list (at decent prices) - you might try red mahogany for something like the bottom guitar, and medium mahogany for the upper one. You'd apply color coats until you get to the shade you want, and then lay on the clear coats until you think you've had enough, then lay on a few more coats after that.
If you want to avoid spray products, there are other ways to skin the cat. I did an alder coffee table using Minwax Pre-Stain Conditioner and a Minwax Wood Finish stain, and it came out pretty good. You can have the Minwax tinted to various shades - see their website for details.
You could also use a gel product, which gives superior control vs. a dye color-coat or a conventional oil-based stain. Some folks around here use Behlen's over statin, others use Minwax products.