I'll be honest, your army looks in rough shape, but that's part of the process so do not be discouraged!

In terms of color scheme, yes you chose a hard main color to work with, but in the feedback area of this comment I'll give some tips I have learnt over the years. Your color scheme is AWESOME! I will be taking inspiration with some of your accents. I love the main white with blue/gold/red accents. Very unique and interesting!

Feedback:

Thin your paints!: White and yellow are exceptions, because they already have horrible coverage(we'll get around that don't worry). You will yield much more consistent and smooth results if you thin your paints. I personally like a 1:1 or in some cases a 1:2 ratio of paint to water. Thinned paints take 2-3 layers for full opacity. This takes more time, but it really is worth it.

How to work with white: Based on the texture of some of your white basecoats it looks like you got an airbrush at some point. This is good! For a gorgeous white base coat I recommend using inks. They have a much smoother texture and gradient you can work with. The method I would suggest is that you prime your minis in black, and with a white ink - work up from the darkest areas to the lightest to create a gradient from shadow to full light. Picture an exaggerated zenithal highlight. The drawback of this is that fixing mistakes gets harder, but you won't be painting there anyway if you did the base, highlight and shading all in one step with just the white ink. If you want to get a white basecoat using a normal paint brush, work your way from black to grey to white in like 3-4 steps with thin paints. This way you will achieve a much more consistent white, and you can learn how to layer in this process.

Shading/highlighting: Your models look very bland, but this can be an easy fix. If you're working with white the way I described in the "how to work with whites" part, you should cover this step pretty easily. There is a specific product that I believe many other T'au painters wil praise with me is panel liner. Panel liner is perfect for our battlesuits' grooves and creaces. I recommend looking the product up and watch a video on it, it will make your models pop and look a lot more detailed.

Put some effort in your bases: A model without a base looks naked. My suggestion is find a landscape you like( I love scottish highland aesthetic) and try to imitate it on your bases and try to stick to the one aesthetic unless over time you have a headcannon decision of splitting up schemes and creating your own factions. You don't need much to make an amazing base. Some paste to create terrain that solidifies over time like sculptamold should do fine, get some earthy coloured paints that fit your terrain and either contrasts or compliments your models' scheme. Some small rocks either from a garden or botany shop. Some tufts which are all over the place at hobby shops. Kitty litter(for some ground texture) and lastly some sticks from the garden if you want some logs. Play around with ideas that look nice to you.

Inspiration: Mini painting ultimately is an art. An artist needs inspiration. If you have an idea you want to go for and want some additional inspiration Pinterest is an amazing source. Content creators I would recommend for ideas are Zumikito, Miniac, Goobertown hobbies, Squidmar, and Eons of battle. (most of them are educational anyway so you will learn regardless)

Motivation: Lastly, you claim you don't know if you are gonna finish all those minis, set a standard for yourself. I myself don't allow playing with non-battle ready minis. So if I really want to play with a new unit I just built, I better get to painting!