Gotta agree that the overall scheme is too busy. The white and yellow are very stark contrasting with the black. I prefer the method outlined in Imperial Armor 3; use a two tone base color with small details picked out in a different color.
You can see this in practice on my
old Hammerhead. Things I've done different since that picture is make the exhaust and intake areas flat black. That's because those areas are most likely to attract smoke, grease, and grime effects. I've also used the popular (amongst Tau players anyway) blue for screens, energy effects, and lights.
You've done a great job of applying the color evenly and neatly on your models. In your case, I think you'd be well served to try to highlight and shade your selected colors. You'll probably find it difficult to do the white and black which is why using those colors is a challenge. As someone else pointed out, you may want to observe the dazzle camoflague method. That will serve your bold black and white colors well on the large models, but will not look good on your troops. For that, you'll probably be better served using a black undersuit, white armor, and yellow accents for things like your shoulderpad or guns.
Now that I think about it, you may want to use a very light blue or very pale, light yellow where you are currently using white. You can then use white to do your highlights. The light yellow (Vallejo Pale Sand may be a good choice) will blend better with your bold yellow and black and permit you to highlight effectively.
Thanks for sharing and best of luck! There's plenty of great ideas in this thread.