It's been said that mandos and stealth don't go together, and for the most part that's certainly true. But when the word "rogue" was mentioned something clicked in my head. I remember having discussions on character roles for tabletop games like D&D, discussions that resemble movie spec-ops training talk because our gamemaster at the time was brutally analytical and ruthlessly intelligent. He once broke down the rogue "types" for me to understand that it isn't about just dumping as many points as I could into stealth and hoping for the best. So here's the breakdown, and how each may relate to you more "stealthy" mando costume.
The Sneaking Rogue - This is the black clad rogue we are all most familiar with and the one that is least mando. The sneaking rogue hides and sneaks and to get what he/she needs. However, leaning so heavily on stealth leaves this rogue fairly combat incapable...which leads to him/her performing ever increasingly amazing feats of sneakyness while being a paranoid mess. For the sneaking rogue detection means death to him/her, whereas for a mando, any mando, it should mean death to someone else.
The Ginsu Rogue - The ginsu rogue, also known as the "slice and dice" rogue and the "combat assassin" rogue is much less tangible to us, often mistaken for just being badshebs period. The ginsu rogue can hold his/her own in combat, but knows better than to try and be the tank holding the killbox shut. Instead, the ginsu rogue fights smarter, finding the right place and time to unleash a fountain of violence. This is the most mando rogue type, as this is how most bounty hunters and black-ops types operate. The ginsu rogue is sneaky, yes, but that sneakyness is less about hiding and slinking, and more about planning and preparation. A ginsu rogue is often where his target least expects, but doesn't need too much stealth to get there.
The Lockpicking Rogue - Also known as the "tool using" rogue or the "skill using" rogue, can be mando if you think about it properly. This is the rogue that always has the right skill or the right tool to resolve any situation... often both with a story to go with them. Considering how heavily equipped a mando can be having the right tool and skill for an unusual situation is often the case. This is where more "techy" mandos come in, as the can indeed lay down a lot of heat in a fight but instead focus on doing all the little "odd-jobs" that may come up to help their more combat driven comrades. Read some of the comics with Boba in them...you'll find yourself saying "where does he get all those wonderful toys?"
So here's the summary. If you want to make a rogue-like mando, don't focus on being "stealthy", but instead focus on being "roguey". A sneaking rogue mando simply won't work, a ginsu rogue mando would be great, and a lockpicking rogue mando would just be...another techy mando. I hope that helps you plan out your theme a bit more easily.
The only other advice I can give for being "roguey" is that understanding how to make less be more. You're going to have to go sleek to get your point across, which means the minimum plates allowed by CRLs with those plates being as smooth as possible. Ignore the idea of trying to "go black" like a ninja and just do whatever colors you think would be fun and unique. Focus on making very high quality and elaborate soft parts to make up for the lack of plates, especially try to integrate varying colors, textures and layers, and try to keep it all close to your body. Minimal gaunts with a few key tools like darts, blades, and line shooters might be a good idea. Think of creative ways to look distinctly mando, and make them very visible but easy to hide, giving the impression that you are proudly mandalorian but very capable of blending in if need be. Remember, its less about being "stealthy", and more about being devious.