Del. Code tit. 12 § 3304
Unless expressly provided otherwise in any instrument specified in § 3303 of this title, any provisions in any such instrument prescribing, defining or limiting the kind of property in which the funds of the trust to which such instrument relates shall be invested shall not apply to any property owned by a testator at the time of the testator's death and delivered to the fiduciary by the personal representative of such testator who has created a trust by the testator's will or delivered by the settlor to the fiduciary of a trust created in a trust agreement or delivered to the fiduciary pursuant to a court order or other instrument creating or defining the fiduciary's duties and powers and such fiduciary may retain all such property so acquired, subject to the limitations of the standards set forth in § 3302 of this title. Furthermore, a provision in any such instrument directing the retention of any such property as a trust investment shall be deemed to waive any duty of diversification otherwise applicable to the fiduciary with respect to such property and shall exonerate the fiduciary from liability for retaining the property except in the case of wilful misconduct proven by clear and convincing evidence in the Court of Chancery.
12 Del. C. § 3304