颜色值通常遵循RGB/ARGB标准，使用时通常以“#”字符开头，以16进制表示。前端开发中一般常用8位十六进制的数值代表颜色，其中前两位代表透明度(alpha)，后两位分别代表(red)(green)(blue)十六进制色值（如#80FFFF00为半透明红色色值）。透明度分为256个等级，即 0 - 256，0就是透明，255就是不透明，对应着16进制 （透明）00 –> FF（不透明）。
- RGB颜色值与十六进制颜色码转换工具：www.sioe.cn/yingyong/ya…
- 在react native开发中略有不同，半透明为
backgroundColor: 'rgba(0,0,0,0.5)'
- 在android开发中设置透明度
View v = findViewById(R.id.content);//找到你要设透明背景的layout 的id
v.getBackground().setAlpha(100);//0~255透明度值
v.setAlpha(100);//或者
一、常用的色值记录：
| 全透明 | #00000000 |
| 半透明 | #80000000 |
| 不透明 | #FF000000 |
| 白色半透明 | #80FFFFFF |
| 白色 | rgb(255,255,255) |
| 黑色 | rgb(0,0,0) |
| 红色 | rgb(255,0,0) |
| 绿色 | rgb(0,255,0) |
| 蓝色 | rgb(0,0,255) |
| 青色 | rgb(0,255,255) |
| 紫色 | rgb(255,0,255) |
二、各百分比透明度对应16进制值
| 100% | 00 |
| 99% | 03 |
| 98% | 05 |
| 97& | 07 |
| 96% | 0A |
| 95% | 0D |
| 94% | 0F |
| 93% | 12 |
| 92% | 14 |
| 91% | 17 |
| 90% | 1A |
| 89% | 1C |
| 88% | 1E |
| 87% | 21 |
| 86% | 24 |
| 85% | 26 |
| 84% | 29 |
| 83% | 2B |
| 82% | 2E |
| 81% | 30 |
| 80% | 33 |
| 79% | 36 |
| 78% | 38 |
| 77% | 3B |
| 76% | 3D |
| 75% | 40 |
| 74% | 42 |
| 73% | 45 |
| 72% | 47 |
| 71% | 4A |
| 70% | 4D |
| 69% | 4F |
| 68% | 52 |
| 67% | 54 |
| 66% | 57 |
| 65% | 59 |
| 64% | 5C |
| 63% | 5E |
| 62% | 61 |
| 61% | 63 |
| 60% | 66 |
| 59% | 69 |
| 58% | 6B |
| 57% | 6E |
| 56% | 70 |
| 55% | 73 |
| 54% | 75 |
| 53% | 78 |
| 52% | 7A |
| 51% | 7D |
| 50% | 80 |
| 49% | 82 |
| 48% | 85 |
| 47% | 87 |
| 46% | 8A |
| 45% | 8C |
| 44% | 8F |
| 43% | 91 |
| 42% | 94 |
| 41% | 96 |
| 40% | 99 |
| 39% | 9C |
| 38% | 9E |
| 37% | A1 |
| 36% | A3 |
| 35% | A6 |
| 34% | A8 |
| 33% | AB |
| 32% | AD |
| 31% | B0 |
| 30% | B3 |
| 29% | B5 |
| 28% | B8 |
| 27% | BA |
| 26% | BD |
| 25% | BF |
| 24% | C2 |
| 23% | C4 |
| 22% | C7 |
| 21% | C9 |
| 20% | CC |
| 19% | CF |
| 18% | D1 |
| 17% | D4 |
| 16% | D6 |
| 15% | D9 |
| 14% | DB |
| 13% | DE |
| 12% | E0 |
| 11% | E3 |
| 10% | E6 |
| 9% | E8 |
| 8% | EB |
| 7% | ED |
| 6% | F0 |
| 5% | F2 |
| 4% | F5 |
| 3% | F7 |
| 2% | FA |
| 1% | FC |
| 0% | FF |
