Colours on OEBTs

What I find from my 3 months of keeping OEBTs,
- my tier 1 were all SUPER BLUE when I got them, but 1 or 2 turns almost colourless once in a while, the other keep in a very dark blue colour. Breeding hasn't started (I have had them just less than a month).

- My tier 2 shows the same behaviour. Some keep being blue, a few would change from very blue, light blue (like in the pictures in the post), or blondes. Some of them stay blondes all the time.

- When females are berried, they are likely to lose some blue, but when they are saddled and close to get berried, they become a dark colour and their backs turns almost chocolate, normally they get berried in a few days after that.

- Even their eyes can change colour. I see this on a berried OEBT, her eyes would trun from golden/orange to almost white, but never black.

- One of my berried OEBT turns red (the stripes), that makes it look almost like a red tiger with orange eyes. Not exaggerating here, if you see it, you WILL think it's a red tiger than an OEBT.


What I'm trying to find out
- Can selective breeding achieve stable colour?
- Can I actually get Royal Blue from OEBT x OE Black Tigers?
- What would happen when OEBT x red tiger? or OE Black Tiger x red tiger.
- What is the ratio like when blonde OEBT x blonde OEBT? (probably varies, but at least I want to know if at least I get 30% blue offspring?)