The Isabella texture pack is one of those packs that's been flying under the radar for a lot of people. Despite that, it seems to have developed a minor cult following. Looking at it closely, I can see how people might enjoy the pastel color schemes, but as far as creativity and art design go, there are other textures out there that provides a better visual and gameplay experience.
The creator seems to love pastel colors. I do too, but only up to a point. The only splash of bright color you'll see here in this texture pack is in the ores you're mining. Everything else is faded and dark (although I believe this was addressed in one of the recent updates).
As for the designs, a lot of them seem generic and lacking in the creativity department. Mobs look different from their vanilla versions, but the new designs look so similar that the creator needn't have bothered. The zombie design was particularly annoying, as the creator just painted it pastel and sent it out the door.
This texture is worth a look, if only based on the positive user testimonials it seems to be getting, but honestly there are a lot of better packs out there.
1. Download and InstallMCPatcher HD
2. Download Isabella Texture Pack
3. Open the Start menu and click “Run”
4. Type “%appdata%” (without quotes)
5. Find a folder named “/.minecraft/”. Go inside and find a /texturepacks/ folder
6. Copy and paste texture pack .zip file into texturepacks folder
7. Launch Minecraft
8. Change your Texture Pack